…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

Rollup of 15 pull requests

Successful merges:

 - #131477 (Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var)
 - #139806 (std: sys: pal: uefi: Overhaul Time)
 - #144386 (Extract TraitImplHeader in AST/HIR)
 - #144542 (Stabilize `sse4a` and `tbm` target features)
 - #144921 (Don't emit `rustdoc::broken_intra_doc_links` for GitHub-flavored Markdown admonitions like `[!NOTE]`)
 - #145155 (Port `#[allow_internal_unsafe]` to the new attribute system (attempt 2))
 - #145214 (fix: re-enable self-assignment)
 - #145216 (rustdoc: correct negative-to-implicit discriminant display)
 - #145238 (Tweak invalid builtin attribute output)
 - #145249 (Rename entered trace span variables from `_span` to  `_trace`)
 - #145251 (Support using #[unstable_feature_bound] on trait)
 - #145253 (Document compiler and stdlib in stage1 in `pr-check-2` CI job)
 - #145260 (Make explicit guarantees about `Vec`’s allocator)
 - #145263 (Update books)
 - #145273 (Account for new `assert!` desugaring in `!condition` suggestion)

r? `@ghost`
`@rustbot` modify labels: rollup

…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

Rollup of 14 pull requests

Successful merges:

 - #131477 (Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var)
 - #139806 (std: sys: pal: uefi: Overhaul Time)
 - #144210 (std: thread: Return error if setting thread stack size fails)
 - #144386 (Extract TraitImplHeader in AST/HIR)
 - #144921 (Don't emit `rustdoc::broken_intra_doc_links` for GitHub-flavored Markdown admonitions like `[!NOTE]`)
 - #145155 (Port `#[allow_internal_unsafe]` to the new attribute system (attempt 2))
 - #145214 (fix: re-enable self-assignment)
 - #145216 (rustdoc: correct negative-to-implicit discriminant display)
 - #145238 (Tweak invalid builtin attribute output)
 - #145249 (Rename entered trace span variables from `_span` to  `_trace`)
 - #145251 (Support using #[unstable_feature_bound] on trait)
 - #145253 (Document compiler and stdlib in stage1 in `pr-check-2` CI job)
 - #145263 (Update books)
 - #145273 (Account for new `assert!` desugaring in `!condition` suggestion)

r? `@ghost`
`@rustbot` modify labels: rollup

…, r=petrochenkov

fix: re-enable self-assignment

## Description

Re-enables the self-assignment detection that was previously disabled due to unrelated regressions. The fix detects useless assignments like `x = x` and `foo.field = foo.field`.

## History

The original regressions (rust-lang#81626, rust-lang#81658) were specifically about false positives in write-only field detection, not self-assignment detection. Belows are brief history for the rule that I understand.

- Self-assignment detection was originally implemented in rust-lang#87129 to address rust-lang#75356
- The implementation was disabled alongside the revert of rust-lang#81473's "write-only fields" detection
- rust-lang#81473 was reverted via rust-lang#86212 and rust-lang#83171 due to false positives in write-only field detection (rust-lang#81626, rust-lang#81658)
- The self-assignment detection feature got removed, even though it wasn't the reason for the problems

This PR only re-enables the self-assignment checks, which are orthogonal to the problematic write-only field analysis.

## Changes
- Removed `#[allow(dead_code)]` from `compiler/rustc_passes/src/dead.rs` file
    - `handle_assign` and
    - `check_for_self_assign`
- Added `ExprKind::Assign` handling in `visit_expr` to call both methods
- Updated test expectations in `tests/ui/lint/dead-code/self-assign.rs`

Rollup of 17 pull requests

Successful merges:

 - #131477 (Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var)
 - #139806 (std: sys: pal: uefi: Overhaul Time)
 - #144210 (std: thread: Return error if setting thread stack size fails)
 - #144386 (Extract TraitImplHeader in AST/HIR)
 - #144921 (Don't emit `rustdoc::broken_intra_doc_links` for GitHub-flavored Markdown admonitions like `[!NOTE]`)
 - #145155 (Port `#[allow_internal_unsafe]` to the new attribute system (attempt 2))
 - #145214 (fix: re-enable self-assignment)
 - #145216 (rustdoc: correct negative-to-implicit discriminant display)
 - #145238 (Tweak invalid builtin attribute output)
 - #145249 (Rename entered trace span variables from `_span` to  `_trace`)
 - #145251 (Support using #[unstable_feature_bound] on trait)
 - #145253 (Document compiler and stdlib in stage1 in `pr-check-2` CI job)
 - #145260 (Make explicit guarantees about `Vec`’s allocator)
 - #145263 (Update books)
 - #145273 (Account for new `assert!` desugaring in `!condition` suggestion)
 - #145283 (Make I-miscompile imply I-prioritize)
 - #145291 (bootstrap: Only warn about `rust.debug-assertions` if downloading rustc)

r? `@ghost`
`@rustbot` modify labels: rollup