Fix ICE in #63135

Author: ExpHP

src/libsyntax/parse/parser.rs

@@ -3620,7 +3620,15 @@ impl<'a> Parser<'a> {
         let mut etc_span = None;
 
         while self.token != token::CloseDelim(token::Brace) {
-            let attrs = self.parse_outer_attributes()?;
+            let attrs = match self.parse_outer_attributes() {
+                Ok(attrs) => attrs,
+                Err(err) => {
+                    if let Some(mut delayed) = delayed_err {
+                        delayed.emit();
+                    }
+                    return Err(err);
+                },
+            };
             let lo = self.token.span;
 
             // check that a comma comes after every field

src/test/ui/parser/issue-63135.rs

@@ -0,0 +1,3 @@
+// error-pattern: aborting due to 6 previous errors
+
+fn i(n{...,f #

src/test/ui/parser/issue-63135.stderr

@@ -0,0 +1,44 @@
+error: this file contains an un-closed delimiter
+  --> $DIR/issue-63135.rs:3:16
+   |
+LL | fn i(n{...,f #
+   |     - -        ^
+   |     | |
+   |     | un-closed delimiter
+   |     un-closed delimiter
+
+error: expected field pattern, found `...`
+  --> $DIR/issue-63135.rs:3:8
+   |
+LL | fn i(n{...,f #
+   |        ^^^ help: to omit remaining fields, use one fewer `.`: `..`
+
+error: expected `}`, found `,`
+  --> $DIR/issue-63135.rs:3:11
+   |
+LL | fn i(n{...,f #
+   |        ---^
+   |        |  |
+   |        |  expected `}`
+   |        `..` must be at the end and cannot have a trailing comma
+
+error: expected `[`, found `}`
+  --> $DIR/issue-63135.rs:3:15
+   |
+LL | fn i(n{...,f #
+   |               ^ expected `[`
+
+error: expected `:`, found `)`
+  --> $DIR/issue-63135.rs:3:15
+   |
+LL | fn i(n{...,f #
+   |               ^ expected `:`
+
+error: expected one of `->`, `where`, or `{`, found `<eof>`
+  --> $DIR/issue-63135.rs:3:15
+   |
+LL | fn i(n{...,f #
+   |               ^ expected one of `->`, `where`, or `{` here
+
+error: aborting due to 6 previous errors
+