Most of the changes fall into a few categories:
* Replace explicit "x86_64" with %target-cpu in lit tests
* Cope with architecture differences in IR/asm/etc. macOS-specific tests
This changes the Swift resource directory from looking like
lib/
swift/
macosx/
libswiftCore.dylib
libswiftDarwin.dylib
x86_64/
Swift.swiftmodule
Swift.swiftdoc
Darwin.swiftmodule
Darwin.swiftdoc
to
lib/
swift/
macosx/
libswiftCore.dylib
libswiftDarwin.dylib
Swift.swiftmodule/
x86_64.swiftmodule
x86_64.swiftdoc
Darwin.swiftmodule/
x86_64.swiftmodule
x86_64.swiftdoc
matching the layout we use for multi-architecture swiftmodules
everywhere else (particularly frameworks).
There's no change in this commit to how Linux swiftmodules are
packaged. There's been past interest in going the /opposite/ direction
for Linux, since there's not standard support for fat
(multi-architecture) .so libraries. Moving the .so search path /down/
to an architecture-specific directory on Linux would allow the same
resource directory to be used for both host-compiling and
cross-compiling.
rdar://problem/43545560
