Be case sensitive when determining driver mode based on argv[0] except on Windows

This narrows the impact of r188833 after Dimitry pointed out that it's good to be
able to tell the difference between 'cc' and 'CC'.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203624 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Remove debug-info-pubtypes.ccp - pubnames/pubtypes are adequately tested in LLVM now.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203625 91177308-0d34-0410-b5e6-96231b3b80d8