for TestNamespaceLookup.py; didn't see anything obviously wrong so I'll
need to look at this more closely before re-committing. (passed OK on
macOS ;)
llvm-svn: 273531
There's uses of "macosx" that will be more tricky to
change, like in triples (e.g. "x86_64-apple-macosx10.11") -
for now I'm just updating source comments and strings printed
for humans.
llvm-svn: 273524