Sometimes features are removed from `Features.def`, but they are not
removed from the test files. The compiler ignores every feature that
does not exist. This leads to removed features still being tested, and
with the introduction of #76740, `REQUIRED:`.
Modify the code that generates the active feature set for testing to
also generate the set of existing features, and pass this list of
existing features to the verifier script. If a feature is trying to be
activated and does not exist, the verifier will warn the user.
- `SwiftParser` feature was renamed `ParserASTGen`, but some tests were
using both spellings. Remove the mentions of `SwiftParser` in the
tests.
- `ImportObjcForwardDeclarations` was spelled with upper case `C` in
a couple of tests. Fix it so the matching is easier.
- `TransferringArgsAndResults` was an experimental feature that was
removed.
- Ignore the usage of inexisting feature in `swift-export-as.swift`
because it seems to be what the test is actually testing.
- Ignore the test `availability_define.swift` because it tests the
pseudo-feature `AvailabilityMacro=` which is not part of
`Features.def`.
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.
Instead, use the `%target-swift-5.1-abi-triple` substitution to compile the tests
for deployment to the minimum OS versions required for use of _Concurrency APIs.
Specifically:
1. CheckedContinuation.resume now takes a sending parameter.
2. Async{Throwing,}Stream.yield takes a sending parameter.
3. withCheckedContinuation returns a transferring parameter.
Importantly due to the previous changes around mangling, this is a mangling
neutral change.
rdar://120420024
