Pass type when creating load

This makes load generation compatible with opaque pointers.

The generation of nontemporal copies still accesses the pointer
element type, as fixing this requires more movement.

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -289,6 +289,15 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> {
         }
         match self {
             OperandValue::Ref(r, None, source_align) => {
+                if flags.contains(MemFlags::NONTEMPORAL) {
+                    // HACK(nox): This is inefficient but there is no nontemporal memcpy.
+                    // FIXME: Don't access pointer element type.
+                    let ty = bx.element_type(bx.val_ty(r));
+                    let val = bx.load(ty, r, source_align);
+                    let ptr = bx.pointercast(dest.llval, bx.type_ptr_to(ty));
+                    bx.store_with_flags(val, ptr, dest.align, flags);
+                    return;
+                }
                 base::memcpy_ty(bx, dest.llval, dest.align, r, source_align, dest.layout, flags)
             }
             OperandValue::Ref(_, Some(_), _) => {