Fix incorrect semicolon suggestion

Author: estebank

Diff for: src/libsyntax/ext/expand.rs

@@ -1044,7 +1044,9 @@ impl<'a> Parser<'a> {
             );
             err.note(&msg);
             let semi_span = self.sess.source_map().next_point(span);
-            match self.sess.source_map().span_to_snippet(semi_span) {
+
+            let semi_full_span = semi_span.to(self.sess.source_map().next_point(semi_span));
+            match self.sess.source_map().span_to_snippet(semi_full_span) {
                 Ok(ref snippet) if &snippet[..] != ";" && kind_name == "expression" => {
                     err.span_suggestion_with_applicability(
                         semi_span,

Diff for: src/test/ui/macros/macro-context.stderr

@@ -16,9 +16,7 @@ LL |     () => ( i ; typeof );   //~ ERROR expected expression, found reserved k
    |                 ^^^^^^
 ...
 LL |     let i = m!();
-   |             ----- help: you might be missing a semicolon here: `;`
-   |             |
-   |             caused by the macro expansion here
+   |             ---- caused by the macro expansion here
    |
    = note: the usage of `m!` is likely invalid in expression context