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.
This means that:
1. In test cases where minimal is the default (swift 5 without
-warn-concurrency), I added RUN lines for targeted, complete, and complete +
sns.
2. In test cases where complete is the default (swift 6, -warn-concurrency,
specified complete with -strict-concurrency), I added a send non-sendable run
line.
In each of these cases, I added additional expected-* lines as appropriate so
the tests can compile in each mode successfully.
The underlying problem was that the ActorIsolationChecker was not properly
recording the mutation environment in which a lookup through an existential was
happening. That's because the AST looks like this:
```
(inout_expr ...
(open_existential_expr ...
(opaque_value_expr ...
(declref_expr ...
(member_ref_expr ...
(opaque_value_expr ...
```
and the walker creates a link from the `open_existential_expr` to the `inout_expr`,
but that kind of expression is not checked for its usage environment. Instead, we
need to look through that OpenExistentialExpr recursively so that a link from
its sub-expression, the `member_ref_expr`, to the `inout_expr` is formed instead.
The side-effect of that missing link causing the bug is that the `usageEnv` of
that `member_ref_expr` appears to be empty when we don't have the link. A missing
link is assumed to mean that it's not in a mutating environment, and thus the
usage is treated as a read.
This is why in #59573 / rdar://95509917 we are seeing the compiler report that an
`await` is needed around the assignment expr. The checker thinks it's a read, but
it's actually a mutation, because the member ref is happening in an `inout` expr.
Resolves rdar://95509917
Resolves#59573
