add test for delimiter mismatch

Author: chenyukang

src/test/ui/parser/issue-68987-unmatch-issue-1.rs

@@ -0,0 +1,12 @@
+// This file has unexpected closing delimiter,
+
+fn func(o: Option<u32>) {
+    match o {
+        Some(_x) => {}   // Extra '}'
+            let _ = if true {};
+        }
+        None => {}
+    }
+} //~ ERROR unexpected closing delimiter
+
+fn main() {}

src/test/ui/parser/issue-68987-unmatch-issue-1.stderr

@@ -0,0 +1,14 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/issue-68987-unmatch-issue-1.rs:10:1
+   |
+LL |     match o {
+   |             - this delimiter might not be properly closed...
+...
+LL |         }
+   |         - ...as it matches this but it has different indentation
+...
+LL | }
+   | ^ unexpected closing delimiter
+
+error: aborting due to previous error
+

src/test/ui/parser/issue-68987-unmatch-issue.rs

@@ -2,7 +2,7 @@
 
 fn func(o: Option<u32>) {
     match o {
-        Some(_x) =>
+        Some(_x) =>   // Missing '{'
             let _ = if true {};
         }
         None => {}