For PR351:
Create new variables LLVM_ON_UNIX and LLVM_ON_WIN32 so we can start getting
rid of reliance upon a symbolic link to switch implementations in lib/System


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19131 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed