When a target does not support pragma detect_mismatch, an llvm.linker.options
metadata with an empty entry is created, which causes diagnostic in backend
since backend expects name/value pair in llvm.linker.options entries.
This patch fixes that.
Differential Revision: https://reviews.llvm.org/D69678
We would incorrectly emit the directive sections due to the missing overridden
methods. We now emit the expected "/DEFAULTLIB" rather than "-l" options for
requested linkage
llvm-svn: 273558