Backslash followed by # in a filename should have both characters
escaped, if you do it the way GNU Make wants.  GCC doesn't, so we do
it the way GCC does rather than the way GNU Make wants.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@237304 91177308-0d34-0410-b5e6-96231b3b80d8