The MinGW linker supports response files
The MinGW linker supports response files

This affects both LLD and ld.bfd.

This isn't testable with a normal driver test with -### because those
command lines are printed before response file setup. I tested manually
and confirmed it seems to do the right thing.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@367733 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang