[clang] [ObjCDirectPreconditionThunk] Adding a flag to with objc_direct symbols' prefix (PR #170616)

[Kyungwoo Lee via cfe-commits]

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@@ -3775,6 +3775,11 @@ defm objc_avoid_heapify_local_blocks : BoolFOption<"objc-avoid-heapify-local-blo
   PosFlag<SetTrue, [], [ClangOption], "Try">,
   NegFlag<SetFalse, [], [ClangOption], "Don't try">,
   BothFlags<[], [CC1Option], " to avoid heapifying local blocks">>;
+defm objc_direct_precondition_thunk : BoolFOption<"objc-direct-precondition-thunk",
+  CodeGenOpts<"ObjCDirectPreconditionThunk">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Move direct methods' precondition checks to thunks">,
----------------
kyulee-com wrote:

```suggestion
          "Move precondition checks for direct methods into thunks">,
```

https://github.com/llvm/llvm-project/pull/170616