Updating PPC target to ignore commas in asm contrains, as apparently that is what gcc does.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107953 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Basic/Targets.cpp

@@ -449,6 +449,8 @@ public:
                                      TargetInfo::ConstraintInfo &Info) const {
     switch (*Name) {
     default: return false;
+    case ',': // Ignore ','s
+      break;
     case 'O': // Zero
       break;
     case 'b': // Base register