Reduce test case

src/test/ui/issues/issue-58856-1.rs

@@ -1,12 +1,6 @@
-struct A;
-
 impl A {
-    fn b(self> {}
+    fn b(self>
     //~^ ERROR expected one of `)`, `,`, or `:`, found `>`
 }
 
-// verify that mismatched delimiters get emitted
-fn foo(] {}
-//~^ ERROR incorrect close delimiter
-
 fn main() {}

src/test/ui/issues/issue-58856-1.stderr

@@ -1,19 +1,11 @@
 error: expected one of `)`, `,`, or `:`, found `>`
-  --> $DIR/issue-58856-1.rs:4:14
+  --> $DIR/issue-58856-1.rs:2:14
    |
-LL |     fn b(self> {}
+LL |     fn b(self>
    |         -    ^
    |         |    |
    |         |    help: `)` may belong here
    |         unclosed delimiter
 
-error: incorrect close delimiter: `]`
-  --> $DIR/issue-58856-1.rs:9:8
-   |
-LL | fn foo(] {}
-   |       -^ incorrect close delimiter
-   |       |
-   |       un-closed delimiter
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error