Summary:
This change adds an arch-specific subdirectory in <ResourceDir>/lib/<OS>
to the linker search path. This path also gets added as '-rpath' for
native compilation if a runtime is linked in as a shared object. This
allows arch-specific libraries to be installed alongside clang.
Reviewers: danalbert, cbergstrom, javed.absar
Subscribers: srhines
Differential Revision: https://reviews.llvm.org/D30015
llvm-svn: 296927