[clang] [CIR] Add proper handling for no prototype function calls (PR #150553)

[Sirui Mu via cfe-commits]

================
@@ -1805,7 +1887,9 @@ CIRGenModule::createCIRFunction(mlir::Location loc, StringRef name,
     func = builder.create<cir::FuncOp>(loc, name, funcType);
 
     assert(!cir::MissingFeatures::opFuncAstDeclAttr());
-    assert(!cir::MissingFeatures::opFuncNoProto());
+
+    if (funcDecl && !funcDecl->hasPrototype())
+      func.setNoProtoAttr(builder.getUnitAttr());
----------------
Lancern wrote:

```suggestion
      func.setNoProto(true);
```

https://github.com/llvm/llvm-project/pull/150553