For #pragma comment(linker, ...) MSVC expects the comment string to be quoted, but for #pragma comment(lib, ...) the compiler itself quotes the library name.
Since this distinction disappears by the time the directive reaches the backend, move quoting for the "lib" version to the frontend.
Differential Revision: http://reviews.llvm.org/D7652
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229375 91177308-0d34-0410-b5e6-96231b3b80d8
