Allow 'extract index' in top-level inference.

pkg/analyzer/test/src/summary/top_level_inference_test.dart

Index: pkg/analyzer/test/src/summary/top_level_inference_test.dart
diff --git a/pkg/analyzer/test/src/summary/top_level_inference_test.dart b/pkg/analyzer/test/src/summary/top_level_inference_test.dart
index c0ef180e6040876798a7b3ebc5dc8c894435cb67..b817ac070a06b0278af48bbf84525a31e5dd6d01 100644
--- a/pkg/analyzer/test/src/summary/top_level_inference_test.dart
+++ b/pkg/analyzer/test/src/summary/top_level_inference_test.dart
@@ -127,6 +127,15 @@ var t2 = ((a = 1) == 0) != ((a = 2) == 0);
     await checkFile(content);
   }
 
+  test_initializer_extractIndex() async {
+    var content = r'''
+var a = /*info:INFERRED_TYPE_LITERAL*/[0, 1.2];
+var b0 = a[0];
+var b1 = a[1];
+''';
+    await checkFile(content);
+  }
+
   test_initializer_functionLiteral_blockBody() async {
     var content = r'''
 var t = /*error:TOP_LEVEL_FUNCTION_LITERAL_BLOCK*/
@@ -871,6 +880,21 @@ dynamic x/*error: instanceGetter*/;
 ''');
   }
 
+  test_initializer_extractIndex() async {
+    var library = await _encodeDecodeLibrary(r'''
+var a = [0, 1.2];
+var b0 = a[0];
+var b1 = a[1];
+''');
+    checkElementText(
+        library,
+        r'''
+List<num> a;
+num b0;
+num b1;
+''');
+  }
+
   test_initializer_functionExpression() async {
     var library = await _encodeDecodeLibrary(r'''
 import 'dart:async';