[clang] [llvm] [aarch64][x86][win] Add compiler support for MSVC's /funcoverride flag (Windows kernel loader replaceable functions) (PR #125320)

[Daniel Paoliello via llvm-commits]

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@@ -7613,6 +7613,9 @@ def import_call_optimization : Flag<["-"], "import-call-optimization">,
              "by the Windows kernel to enable import call optimization">,
     MarshallingInfoFlag<CodeGenOpts<"ImportCallOptimization">>;
 
+def replaceable_function: Joined<["-"], "loader-replaceable-function=">,
+  MarshallingInfoStringVector<CodeGenOpts<"LoaderReplaceableFunctionNames">>;
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dpaoliello wrote:

We only expect to use this via clang-cl, so if someone wants a clang option they can add that later.

https://github.com/llvm/llvm-project/pull/125320