* afl-cc header

* afl-cc common declarations

 - Add afl-cc-state.c
 - Strip includes, find_object, debug/be_quiet/have_*/callname setting from afl-cc.c
 - Use debugf_args in main
 - Modify execvp stuffs to fit new aflcc struct

* afl-cc show usage

* afl-cc mode selecting

1. compiler_mode by callname in argv[0]
2. compiler_mode by env "AFL_CC_COMPILER"
3. compiler_mode/instrument_mode by command line options "--afl-..."
4. instrument_mode/compiler_mode by various env vars including "AFL_LLVM_INSTRUMENT"
5. final checking steps
6. print "... - mode: %s-%s\n"
7. determine real argv[0] according to compiler_mode

* afl-cc macro defs

* afl-cc linking behaviors

* afl-cc fsanitize behaviors

* afl-cc misc

* afl-cc body update

* afl-cc all-in-one

formated with custom-format.py

* nits

---------

Co-authored-by: vanhauser-thc <vh@thc.org>

Make the compiler wrapper stripping `-Wl,-no-undefined` in addition to `-Wl,--no-undefined`.
Both versions of the flag are accepted by clang and, therefore, used by building systems in the wild (e.g., samba will not build without this fix).

The custom_mutators_count check in if case is duplicate with if condition.
The else case is custom_mutators_count == 0, neither custom_mutator_list iteration nor sent check needed.

Signed-off-by: Xeonacid <h.dwwwwww@gmail.com>

* Document new drcov QEMU plugin

* Add link to lightkeeper for QEMU drcov file loading

---------

Co-authored-by: Jean-Romain Garnier <jean-romain.garnier@airbus.com>

#1958)

* Always compile with -ldl when building for CODE_COVERAGE

When building with CODE_COVERAGE, the afl runtime contains code that
calls `dladdr` which requires -ldl. Under most circumstances, clang
already adds this (e.g. when building with pc-table), but there are some
circumstances where it isn't added automatically.

* Add visibility declaration to __afl_connected

When building with hidden visibility, the use of __AFL_LOOP inside such
code can cause linker errors due to __afl_connected being declared
"hidden".

* Update docs to clarify that CODE_COVERAGE=1 is required for dynamic_covfilter

* update response file support

 - full support of rsp file
 - fix some segv issues

* Improve afl-cc

 - remove dead code about allow/denylist options of sancov
 - missing `if (!aflcc->have_msan)`
 - add docs for each function
 - typo