Go 1.16 has been released just a few days ago, and the latest Go version that GopherJS supported was 1.12, so we need to catch up. Note that this issue covers only the standard library and language support, Go Modules are tracked in #855.

After speaking with @flimzy and other folks we've decided that it's best to jump straight Go 1.16 version, without providing separate releases for intermediate versions. The major reasons behind this choice are:

1. Making multiple additional releases is a lot of work that we really can't afford now.
2. If we support Go 1.16 we should still be able to build Go code for earlier versions without any significant issues thanks to the Go backward compatibility policy.
3. The value of these releases will also quickly diminish as the time passes.

In terms of how to proceed we have two options:

1. Pull in changes from @visualfc's fork (https://github.com/goplusjs/gopherjs), which already pretty much supports everything we need. However, I would like to get @visualfc's permission before we do that to make sure there won't be any bad feelings left between the two projects.
   • As a side note, this won't be a very straight-forward pull since @visualfc's fork uses different import paths and whatnot, but still it is much, much easier.
2. As a plan B, we could also reimplement everything ourselves. This will be a lot of work and create more divergence between the forks, but is still doable.