issue a friendlier error if someone tries to send precompiled header to '-' (stdout)
this brings the error on
  clang -c foo.h -o -
closer to
  clang -c foo.h -o /dev/null

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89948 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed