[PS4] Undo dialect tweak for Objective-C.

In r267772, we had set the PS4's default dialect for both C and
Objective-C to gnu99.  Make that change only for C; we don't really
support Objective-C/C++ so there's no point fiddling the dialect.

llvm-svn: 289625
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index e243cf2..989feef 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1558,14 +1558,16 @@
     case IK_Asm:
     case IK_C:
     case IK_PreprocessedC:
-    case IK_ObjC:
-    case IK_PreprocessedObjC:
       // The PS4 uses C99 as the default C standard.
       if (T.isPS4())
         LangStd = LangStandard::lang_gnu99;
       else
         LangStd = LangStandard::lang_gnu11;
       break;
+    case IK_ObjC:
+    case IK_PreprocessedObjC:
+      LangStd = LangStandard::lang_gnu11;
+      break;
     case IK_CXX:
     case IK_PreprocessedCXX:
     case IK_ObjCXX: