error: expected one of `.`, `;`, `?`, `else`, or an operator, found `""`
  --> $DIR/issue-37234.rs:3:19
   |
LL |         let x = 5 "";
   |                   ^^ expected one of `.`, `;`, `?`, `else`, or an operator
...
LL |     failed!();
   |     --------- in this macro invocation
   |
   = note: this error originates in the macro `failed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 1 previous error