Revert part of r161175 which was wrong for OpenBSD's PowerPC target.

Contributed by Brad Smith <brad@comstyle.com>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161481 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Basic/Targets.cpp

@@ -957,7 +957,6 @@ public:
     case llvm::Triple::Linux:
     case llvm::Triple::FreeBSD:
     case llvm::Triple::NetBSD:
-    case llvm::Triple::OpenBSD:
       SizeType = UnsignedInt;
       PtrDiffType = SignedInt;
       IntPtrType = SignedInt;