[modules] If we import a module, and we've seen a module map that describes the
module, use the path from the module map file in preference to the path from
the .pcm file when resolving relative paths in the .pcm file. This allows
diagnostics (and .d output) to give relative paths if the module was found via
a relative path.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223577 91177308-0d34-0410-b5e6-96231b3b80d8
Rename a couple of preprocessor symbols to be more descriptive. NFC.
Review feedback from recent changes to GetSVN.cmake.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223578 91177308-0d34-0410-b5e6-96231b3b80d8
Add test file missed from r223561.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223595 91177308-0d34-0410-b5e6-96231b3b80d8
Add some file content to avoid test failures on content-addressed file systems.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223596 91177308-0d34-0410-b5e6-96231b3b80d8