Add a test

Author: osa1

src/test/rustdoc-ui/issue-80992.rs

@@ -0,0 +1,11 @@
+// check-pass
+// compile-flags:--test
+// normalize-stdout-test: "src/test/rustdoc-ui" -> "$$DIR"
+// normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
+
+pub fn test() -> Result<(), ()> {
+    //! ```compile_fail
+    //! fn test() -> Result< {}
+    //! ```
+    Ok(())
+}

src/test/rustdoc-ui/issue-80992.stdout

@@ -0,0 +1,6 @@
+
+running 1 test
+test $DIR/issue-80992.rs - test (line 7) ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+