[FMV] Emit the resolver along with the default version definition.

We would like the resolver to be generated eagerly, even if the
versioned function is not called from the current translation
unit. Fixes #81494.

Author: labrinea

clang/lib/CodeGen/CodeGenModule.cpp

@@ -3969,8 +3969,11 @@ void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
         EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
     // Ensure that the resolver function is also emitted.
     GetOrCreateMultiVersionResolver(GD);
-  } else if (FD->hasAttr<TargetVersionAttr>()) {
-    GetOrCreateMultiVersionResolver(GD);
+  } else if (auto *TVA = FD->getAttr<TargetVersionAttr>()) {
+    EmitGlobalFunctionDefinition(GD, GV);
+    // Emit the resolver alongside with the default version definition.
+    if (TVA->isDefaultVersion() && FD->doesThisDeclarationHaveABody())
+      GetOrCreateMultiVersionResolver(GD);
   } else
     EmitGlobalFunctionDefinition(GD, GV);
 }