[analysis_server] Fix occurrences highlighting for prefixed identifiers

Fixes #56981

Change-Id: I817625962b5a4975ec5f597ab147fe7312cdf06f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/392580
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: DanTup

pkg/analysis_server/lib/src/domains/analysis/occurrences_dart.dart

@@ -121,7 +121,7 @@ class _DartUnitOccurrencesComputerVisitor extends RecursiveAstVisitor<void> {
   void visitNamedType(NamedType node) {
     var element = node.element;
     if (element != null) {
-      _addOccurrence(element, node.offset);
+      _addOccurrence(element, node.name2.offset);
     }
 
     super.visitNamedType(node);

pkg/analysis_server/test/analysis/notification_occurrences_test.dart

@@ -682,6 +682,19 @@ import 'dart:io' as /*[0*/_/*0]*/;
     );
   }
 
+  Future<void> test_prefixed() async {
+    await assertOccurrences(
+      kind: ElementKind.CLASS,
+      '''
+import '' as p;
+
+class /*[0*/A/*0]*/ {}
+
+p./*[1*/A/*1]*/? a;
+''',
+    );
+  }
+
   Future<void> test_recordType_typeName() async {
     await assertOccurrences(
       kind: ElementKind.CLASS,

pkg/analysis_server/test/lsp/document_highlights_test.dart

@@ -148,6 +148,14 @@ void f() {
     /*[2*/key/*2]*/;
   }
 }
+''');
+
+  Future<void> test_prefixed() => _testMarkedContent('''
+import '' as p;
+
+class /*[0*/A^/*0]*/ {}
+
+p./*[1*/A/*1]*/? a;
 ''');
 
   Future<void> test_shadow_inner() => _testMarkedContent('''