ObjectiveC driver. reinstate -fno-objc-legacy-dispatch behavior 
when the deployment target is 10.5. // rdar://15852259

llvm-svn: 199682
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 92f35f3..699d7cf 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3324,9 +3324,10 @@
   ObjCRuntime objcRuntime = AddObjCRuntimeArgs(Args, CmdArgs, rewriteKind);
 
   // -fobjc-dispatch-method is only relevant with the nonfragile-abi, and
-  // legacy is the default. Next runtime is always legacy dispatch and
-  // -fno-objc-legacy-dispatch gets ignored silently.
-  if (objcRuntime.isNonFragile() && !objcRuntime.isNeXTFamily()) {
+  // legacy is the default. Except for deployment taget of 10.5,
+  // next runtime is always legacy dispatch and -fno-objc-legacy-dispatch
+  // gets ignored silently.
+  if (objcRuntime.isNonFragile()) {
     if (!Args.hasFlag(options::OPT_fobjc_legacy_dispatch,
                       options::OPT_fno_objc_legacy_dispatch,
                       objcRuntime.isLegacyDispatchDefaultForArch(