...and remove the option. This is ~technically~ CLI-breaking because
Swift 5 shipped this as a hidden driver option, but it wouldn't have
/done/ anything in Swift 5, so I think it's okay to remove.
Note that if a parseable interface (.swiftinterface) and a binary
interface (.swiftmodule) are both present, the binary one will still
be preferred. This just /allows/ parseable interfaces to be used.
rdar://problem/36885834
- Use the name for the cached module, so that we don't end up with a
zillion "x86_64-XXXXXXXX.swiftmodule" files in the cache when we're
working with architecture-specific swiftmodules.
- Diagnose if the expected name is different from the name specified
in the swiftinterface.
- Emit all diagnostics at the location of the import, instead of
without any location at all.
