The new library, swiftEmbeddedPlatformPOSIX, implements all of the
_swift_XYZ functions needed to support Embedded Swift as shims on top
of a POSIX system that provides posix_memalign, free, putchar, and so
on. This offers an easier way to bridge between the prior ad hoc
requirements of Embedded Swift and the newer platform abstraction
layer.
Part of rdar://164057124
Find all the usages of `--enable-experimental-feature` or
`--enable-upcoming-feature` in the tests and replace some of the
`REQUIRES: asserts` to use `REQUIRES: swift-feature-Foo` instead, which
should correctly apply to depending on the asserts/noasserts mode of the
toolchain for each feature.
Remove some comments that talked about enabling asserts since they don't
apply anymore (but I might had miss some).
All this was done with an automated script, so some formatting weirdness
might happen, but I hope I fixed most of those.
There might be some tests that were `REQUIRES: asserts` that might run
in `noasserts` toolchains now. This will normally be because their
feature went from experimental to upcoming/base and the tests were not
updated.
Using inconsistent attributes between stdlib and tests causes
compilation errors. There are still several misuses of @_silgen_name in
tests, but leaving them as is for now to incrementally fix them.