Introduce NullOp::AlignOf

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -648,7 +648,7 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
                 }
             }
 
-            Rvalue::NullaryOp(NullOp::SizeOf, _) => {}
+            Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, _) => {}
             Rvalue::NullaryOp(NullOp::Box, _) => self.check_op(ops::HeapAllocation),
 
             Rvalue::UnaryOp(_, ref operand) => {

compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -520,6 +520,7 @@ impl<'tcx> Validator<'_, 'tcx> {
             Rvalue::NullaryOp(op, _) => match op {
                 NullOp::Box => return Err(Unpromotable),
                 NullOp::SizeOf => {}
+                NullOp::AlignOf => {}
             },
 
             Rvalue::UnaryOp(op, operand) => {