Remove explicit uses of -emit-llvm, the test infrastructure adds it

Remove explicit uses of -emit-llvm, the test infrastructure adds it
automatically.  Use -S with llvm-gcc rather than -c, so tests can
work when llvm-gcc is really dragonegg (which can output IR with -S
but not -c).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120158 91177308-0d34-0410-b5e6-96231b3b80d8