More analyzer updates, and handle negative_tests

lib/src/utils.dart

Index: lib/src/utils.dart
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index df6b054dc8d00002a3bf81876616c74e3c3a061c..229eef40628b14181ea81daca377a647a92b4b54 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -25,7 +25,6 @@ import 'package:analyzer/src/generated/constant.dart' show DartObject;
 //ignore: DEPRECATED_MEMBER_USE
 import 'package:analyzer/src/generated/element.dart' show DynamicTypeImpl;
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
-import 'package:analyzer/src/generated/error.dart' show ErrorCode;
 import 'package:analyzer/src/task/dart.dart' show ParseDartTask;
 import 'package:analyzer/src/generated/resolver.dart' show TypeProvider;
 import 'package:analyzer/src/generated/source.dart' show LineInfo, Source;
@@ -402,22 +401,6 @@ SourceSpanWithContext createSpanHelper(
   return new SourceSpanWithContext(startLoc, endLoc, text, lineText);
 }
 
-String _strongModeErrorPrefix = 'STRONG_MODE';
-
-bool isStrongModeError(ErrorCode errorCode) {
-  return errorCode.name.startsWith(_strongModeErrorPrefix);
-}
-
-String errorCodeName(ErrorCode errorCode) {
-  if (isStrongModeError(errorCode)) {
-    return errorCode.name.substring(_strongModeErrorPrefix.length + 1);
-  } else {
-    // TODO(jmesserly): this is for backwards compat, but not sure it's very
-    // useful to log this.
-    return 'AnalyzerMessage';
-  }
-}
-
 bool isInlineJS(Element e) =>
     e is FunctionElement &&
     e.library.source.uri.toString() == 'dart:_foreign_helper' &&