Add default search path if -nostdlib is not provided.
Add basic emulation mapping for NetBSD/amd64, so that clang -m32 works
as expected.


git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@198337 91177308-0d34-0410-b5e6-96231b3b80d8
No else after return.


git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@198339 91177308-0d34-0410-b5e6-96231b3b80d8