Update navigation region from PatternField.name to the referenced element.

Unfortunately, IntelliJ cannot easily support `foo:`, only `foo`.
So, I update it to navigate from `foo`, explicit or variable.

Bug: #51797
Change-Id: If4cbf553beedf2998cd6ad3fbd7528865b523420
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/290904
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analysis_server/test/analysis/notification_navigation_test.dart

@@ -1289,7 +1289,7 @@ void f(Object? x) {
 ''');
     await prepareNavigation();
 
-    assertHasRegionTarget('foo:', 'foo =>', regionLength: 4);
+    assertHasRegionTarget('foo', 'foo =>');
   }
 
   Future<void> test_objectPattern_patternField_implicitlyNamed() async {
@@ -1304,7 +1304,7 @@ void f(Object? x) {
 ''');
     await prepareNavigation();
 
-    assertHasRegionTarget(': var', 'foo =>', regionLength: 1);
+    assertHasRegionTarget('foo))', 'foo =>');
   }
 
   Future<void> test_objectPattern_patternField_notResolved() async {
@@ -1429,7 +1429,7 @@ void f(Object? x) {
 ''');
     await prepareNavigation();
 
-    assertNoRegionAt('foo:');
+    assertNoRegionAt('foo');
   }
 
   Future<void> test_redirectingConstructorInvocation() async {

pkg/analyzer_plugin/lib/utilities/navigation/navigation_dart.dart

@@ -8,6 +8,7 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/ast/extensions.dart';
 import 'package:analyzer/src/dart/ast/utilities.dart';
 import 'package:analyzer/src/dart/element/element.dart';
@@ -500,8 +501,15 @@ class _DartNavigationComputerVisitor extends RecursiveAstVisitor<void> {
   }
 
   @override
-  void visitPatternField(PatternField node) {
-    computer._addRegionForNode(node.name, node.element);
+  void visitPatternField(covariant PatternFieldImpl node) {
+    final nameNode = node.name;
+    if (nameNode != null) {
+      final nameToken = nameNode.name ?? node.pattern.variablePattern?.name;
+      if (nameToken != null) {
+        computer._addRegionForToken(nameToken, node.element);
+      }
+    }
+
     node.pattern.accept(this);
   }