Always use / when computing mips specific paths.

We were getting paths with both / and \ in them. This should fix mips-cs-ld.c
on the windows bots.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180783 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed