ObjectiveC driver. change to reinstate -fno-objc-legacy-dispatch behavior

when the deployment target is 10.5. // rdar://15852259

llvm-svn: 199780

Author: Fariborz Jahanian

clang/include/clang/Basic/ObjCRuntime.h

@@ -99,14 +99,10 @@ class ObjCRuntime {
           Arch == llvm::Triple::x86_64)
         return false;
     }
-    else if (isNeXTFamily() && getVersion().getMajor() == 10) {
-      unsigned minor = 0;
-      if (getVersion().getMinor().hasValue())
-        minor = getVersion().getMinor().getValue();
-      if (minor == 5 &&
-          (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64))
-        return false;
-    }
+    else if ((getKind() ==  MacOSX) && isNonFragile() &&
+             (getVersion() >= VersionTuple(10, 5)) &&
+             (getVersion() < VersionTuple(10, 6)))
+        return Arch != llvm::Triple::x86_64;
     // Except for deployment target of 10.5,
     // Mac runtimes use legacy dispatch everywhere now.
     return true;