Rename and add another test

tests/mir-opt/const_prop/overwrite_with_const_with_params.rs

@@ -0,0 +1,23 @@
+// unit-test: ConstProp
+// compile-flags: -O
+// skip-filecheck
+
+// Regression test for https://github.com/rust-lang/rust/issues/118328
+
+#![allow(unused_assignments)]
+
+struct SizeOfConst<T>(std::marker::PhantomData<T>);
+impl<T> SizeOfConst<T> {
+    const SIZE: usize = std::mem::size_of::<T>();
+}
+
+// EMIT_MIR overwrite_with_const_with_params.size_of.ConstProp.diff
+fn size_of<T>() -> usize {
+    let mut a = 0;
+    a = SizeOfConst::<T>::SIZE;
+    a
+}
+
+fn main() {
+    assert_eq!(size_of::<u32>(), std::mem::size_of::<u32>());
+}

tests/mir-opt/const_prop/issue_118328.rs → tests/ui/const_prop/overwrite_with_const_with_params.rs

@@ -1,6 +1,8 @@
-// unit-test: ConstProp
 // compile-flags: -O
-// skip-filecheck
+// run-pass
+
+// Regression test for https://github.com/rust-lang/rust/issues/118328
+
 #![allow(unused_assignments)]
 
 struct SizeOfConst<T>(std::marker::PhantomData<T>);