Fix span for await macro call

Author: estebank

src/libsyntax/parse/parser.rs

@@ -2715,7 +2715,7 @@ impl<'a> Parser<'a> {
                 err
             })?;
             self.expect(&token::CloseDelim(token::Paren))?;
-            Ok((expr.span, ExprKind::Await(ast::AwaitOrigin::MacroLike, expr)))
+            Ok((self.prev_span, ExprKind::Await(ast::AwaitOrigin::MacroLike, expr)))
         } else { // Handle `await <expr>`.
             self.parse_incorrect_await_syntax(lo, await_sp)
         }

src/test/ui/feature-gate/await-macro.stderr

@@ -2,7 +2,7 @@ error[E0658]: `await!(<expr>)` macro syntax is unstable, and will soon be remove
   --> $DIR/await-macro.rs:9:5
    |
 LL |     await!(bar());
-   |     ^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50547
    = help: add #![feature(await_macro)] to the crate attributes to enable