Rollup merge of #149950 - WaffleLapkin:inlines-ur-mu-into-asm, r=jdonszelmann

Simplify how inline asm handles `MaybeUninit`

This is just better, but this is also allows it to handle changes from #149614 (i.e. `ManuallyDrop` containing `MaybeDangle`).

Author: Zalathar

src/inline_asm.rs

@@ -857,19 +857,9 @@ fn call_inline_asm<'tcx>(
 
 fn asm_clif_type<'tcx>(fx: &FunctionCx<'_, '_, 'tcx>, ty: Ty<'tcx>) -> Option<types::Type> {
     match ty.kind() {
-        // Adapted from https://github.com/rust-lang/rust/blob/f3c66088610c1b80110297c2d9a8b5f9265b013f/compiler/rustc_hir_analysis/src/check/intrinsicck.rs#L136-L151
+        // Adapted from https://github.com/rust-lang/rust/blob/df44a57fd29fca899ce473f85ed64efd0708dd7c/compiler/rustc_hir_typeck/src/inline_asm.rs#L180-L183
         ty::Adt(adt, args) if fx.tcx.is_lang_item(adt.did(), LangItem::MaybeUninit) => {
-            let fields = &adt.non_enum_variant().fields;
-            let ty = fields[FieldIdx::ONE].ty(fx.tcx, args);
-            let ty::Adt(ty, args) = ty.kind() else {
-                unreachable!("expected first field of `MaybeUninit` to be an ADT")
-            };
-            assert!(
-                ty.is_manually_drop(),
-                "expected first field of `MaybeUninit` to be `ManuallyDrop`"
-            );
-            let fields = &ty.non_enum_variant().fields;
-            let ty = fields[FieldIdx::ZERO].ty(fx.tcx, args);
+            let ty = args.type_at(0);
             fx.clif_type(ty)
         }
         _ => fx.clif_type(ty),