Fix tests so they work when the linker is gcc

If the linker is gcc (the default for Generic_ELF toolchains), we end up
passing most of the arguments to the linker.

Some tests were failing to account for this in their usage of *-NOT: lines
and would fail if compiled with
-DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-unknown

llvm-svn: 228902