* Collect flag in `ParamDecl::setTypeRepr()`.
* [ASTGen] Separate `BridgedParamDecl.setTypeRepr(_:)` from
`BridgedParamDecl.createParsed(_:)` aligning with C++ API. The majority
of the creations don't set the typerepr.
* Update `ParamSpecifierRequest::evaluate` to handle non-implicit
`ParamDecl` without `TypeRepr` (i.e. untyped closure parameter), instead
of `setSpecifier(::Default)` manually in Parse.
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.
These now work because we're doing the transform
in Sema. Closure parameter generation still needs
some extra work unfortunately, so we can't add
tests for that.
