Auto merge of #40272 - jseyfried:fix_const_macro_invocations, r=petrochenkov

macros: fix const expression invocations

Fixes #40136.
r? @nrc

src/test/run-pass/issue-40136.rs

@@ -0,0 +1,24 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(associated_consts)]
+
+macro_rules! m { () => { 0 } }
+
+trait T {
+   const C: i32 = m!();
+}
+
+struct S;
+impl S {
+    const C: i32 = m!();
+}
+
+fn main() {}