[llvm] [VFABI] Improve VFABI unit tests (PR #73907)

[Paul Walker via llvm-commits]

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@@ -38,7 +38,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
       Args.push_back(Constant::getNullValue(ParamTy));
     }
     std::unique_ptr<CallInst> CI(CallInst::Create(F, Args));
-    const auto Info = VFABI::tryDemangleForVFABI(MangledName, *(CI.get()));
+    const auto Info =
+        VFABI::tryDemangleForVFABI(MangledName, CI->getFunctionType());
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paulwalker-arm wrote:

I'm not really familiar with what the fuzzer is doing but I think this whole function can now be simpler given `tryDemangleForVFABI` no longer requires a CallInst and `tryDemangleForVFABI` no longer does a function lookup within the module?

https://github.com/llvm/llvm-project/pull/73907