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.
The compiler reports public imports of non-resilient modules from a
resilient module. Make sure that when imports default to internal, which
also implies Swift 6, this is treated as an error and the fixit simply
deletes the `public` keyword.
We keep using the AccessLevelOnImport flag only to report these as
errors in Swift 5 for early adopters.
Importing a non-library-evolution enabled module from a
library-evolution enabled module will lead to generating a
swiftinterface that can't be rebuilt by a different compiler.
Make it a hard error when using access level imports, and keep it as a
warning for @_implementationOnly imports.
