ccc: Clean up (user level) error handling.
 - ccc now checks for existence of input files (more annoying to test,
   but matches gcc).
 - Fix some test cases.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62378 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed