BuiltinCall

    pub const BuiltinCall = struct {
        // Note: Flags *must* come first so that unusedResultExpr
        // can find it when it goes to modify them.
        flags: Flags,
        modifier: Ref,
        callee: Ref,
        args: Ref,

        pub const Flags = packed struct {
            is_nosuspend: bool,
            ensure_result_used: bool,
            _: u30 = 0,

            comptime {
                if (@sizeOf(Flags) != 4 or @bitSizeOf(Flags) != 32)
                    @compileError("Layout of BuiltinCall.Flags needs to be updated!");
            }
        };
    }