Validate error patterns and error annotation in ui tests when present

Previously, when compilation succeeded, neither error patterns nor error
annotation would be validated. Additionally, when compilation failed,
only error patterns would be validated if both error patterns and error
annotation were present.

Now both error patterns and error annotation are validated when present,
regardless of compilation status. Furthermore, for test that should run,
the error patterns are matched against executable output, which is what
some of tests already expect to happen, and when rust-lang#65506 is merged even
more ui tests will.

src/tools/compiletest/src/runtest.rs

@@ -3137,21 +3137,24 @@ impl<'test> TestCx<'test> {
                     self.fatal_proc_rec("test run succeeded!", &proc_res);
                 }
             }
+            if !self.props.error_patterns.is_empty() {
+                // "// error-pattern" comments
+                self.check_error_patterns(&proc_res.stderr, &proc_res);
+            }
         }
 
         debug!("run_ui_test: explicit={:?} config.compare_mode={:?} expected_errors={:?} \
                proc_res.status={:?} props.error_patterns={:?}",
                explicit, self.config.compare_mode, expected_errors, proc_res.status,
                self.props.error_patterns);
         if !explicit && self.config.compare_mode.is_none() {
-            if !proc_res.status.success() {
-                if !self.props.error_patterns.is_empty() {
-                    // "// error-pattern" comments
-                    self.check_error_patterns(&proc_res.stderr, &proc_res);
-                } else {
-                    // "//~ERROR comments"
-                    self.check_expected_errors(expected_errors, &proc_res);
-                }
+            if !self.should_run() && !self.props.error_patterns.is_empty() {
+                // "// error-pattern" comments
+                self.check_error_patterns(&proc_res.stderr, &proc_res);
+            }
+            if !expected_errors.is_empty() {
+                // "//~ERROR comments"
+                self.check_expected_errors(expected_errors, &proc_res);
             }
         }