Basically everything that has a direct replacement or no uses left.
Notable omissions:
- std.ArrayHashMap: Too much fallout, needs a separate cleanup.
- std.debug.runtime_safety: Too much fallout.
- std.heap.GeneralPurposeAllocator: Lots of references to it remain, not
a simple find and replace as "debug allocator" is not equivalent to
"general purpose allocator".
- std.io.Reader: Is being reworked at the moment.
- std.unicode.utf8Decode(): No replacement, needs a new API first.
- Manifest backwards compat options: Removal would break test data used
by TestFetchBuilder.
- panic handler needs to be a namespace: Many tests still rely on it
being a function, needs a separate cleanup.
Also remove `@frameSize`, closing #3654.
While the other machinery might remain depending on #23446, it is
settled that there will not be `async`/ `await` keywords in the
language.
Evaluate all child processes in the temporary directory, and use
`std.fs.path.relative` to make every other path relative to that child
cwd instead of our cwd.
Resolves: #22119
Instead of introducing YES_COLOR, a completely new standard, into the mix
it might make more sense to instead tag along with the CLICOLOR_FORCE env var,
which dates back to at least 2000 with FreeBSD 4.1.1 and which is
supported by tools like CMake.
<https://bixense.com/clicolors/>
