Switch on null-aware operators by default in analyzer.

pkg/analyzer/lib/src/context/context.dart

Index: pkg/analyzer/lib/src/context/context.dart
diff --git a/pkg/analyzer/lib/src/context/context.dart b/pkg/analyzer/lib/src/context/context.dart
index 095c2938dc4489ac630e17ad90f1a7f48849d092..9c0c9808356e71d72075280b178eba1551f8733c 100644
--- a/pkg/analyzer/lib/src/context/context.dart
+++ b/pkg/analyzer/lib/src/context/context.dart
@@ -239,8 +239,6 @@ class AnalysisContextImpl implements InternalAnalysisContext {
         (this._options.hint && !options.hint) ||
         (this._options.lint && !options.lint) ||
         this._options.preserveComments != options.preserveComments ||
-        this._options.enableNullAwareOperators !=
-            options.enableNullAwareOperators ||
         this._options.enableStrictCallChecks != options.enableStrictCallChecks;
     int cacheSize = options.cacheSize;
     if (this._options.cacheSize != cacheSize) {
@@ -251,7 +249,6 @@ class AnalysisContextImpl implements InternalAnalysisContext {
     this._options.generateImplicitErrors = options.generateImplicitErrors;
     this._options.generateSdkErrors = options.generateSdkErrors;
     this._options.dart2jsHint = options.dart2jsHint;
-    this._options.enableNullAwareOperators = options.enableNullAwareOperators;
     this._options.enableStrictCallChecks = options.enableStrictCallChecks;
     this._options.hint = options.hint;
     this._options.incremental = options.incremental;