[clang] [CIR] Upstream proper function alias lowering (PR #150520)

[Henrich Lauko via cfe-commits]

================
@@ -1166,6 +1199,31 @@ void CIRToLLVMFuncOpLowering::lowerFuncAttributes(
   }
 }
 
+mlir::LogicalResult CIRToLLVMFuncOpLowering::matchAndRewriteAlias(
+    cir::FuncOp op, mlir::FlatSymbolRefAttr aliasee, mlir::Type ty,
----------------
xlauko wrote:

```suggestion
    cir::FuncOp op, llvm::StringRef aliasee, mlir::Type ty,
```

https://github.com/llvm/llvm-project/pull/150520