* [Diagnostics] Update 'does not override' diagnostic message to include protocol context as well
* [Sema] Check whether the override context is a class or a protocol for diagnostic purposes
* [Test] Update tests with new diagnostic message for overrides in protocol context
* [Sema] Adjust diagnostic for overrides in structs and enums to use the existing 'override_nonclass_decl' diagnostic
- Many tests got broken because of two things:
- AST dump now outputs to stdout, but many tests expected stderr. This was a straightforward fix.
- Many tests call swift with specific parameters; specifically, many call `swift frontend` directly. This makes them go through the compiler in unexpected ways, and specifically it makes them not have primary files, which breaks the new AST dump implementation. This commit adds the old implementation as a fallback for those cases, except it dumps to `stdout` to maintain some consistence.
Finally, the `/test/Driver/filelists.swift` failed for unknown reasons. It seems its output now had some lines out of order, and fixing the order made the test pass. However, as the reasons why it failed are unknown, this fix might not have been a good idea. Corrections are welcome.
@_nonoverride is the opposite of override, disabling all override checking
for the given declaration. This can be used to suppress diagnostics related
to declarations that are almost overrides but shouldn’t be or to
intentionally break the override chain; in each case, we’ll end up with
an overload rather than an override.
