[mc-coff] Forward Linker Option flags into the .drectve section

Summary:
This is modelled on the Mach-O linker options implementation and should
support a Clang implementation of #pragma comment(lib/linker).

Reviewers: rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D724

llvm-svn: 180569