Implement the new '?.' operator in analyzer.

pkg/analyzer/test/generated/non_error_resolver_test.dart

Index: pkg/analyzer/test/generated/non_error_resolver_test.dart
diff --git a/pkg/analyzer/test/generated/non_error_resolver_test.dart b/pkg/analyzer/test/generated/non_error_resolver_test.dart
index 33b976963652a1765af50daca70d7932486d3fc3..25ba9fa30c5b02fd9e2d603b780db347f33b88f7 100644
--- a/pkg/analyzer/test/generated/non_error_resolver_test.dart
+++ b/pkg/analyzer/test/generated/non_error_resolver_test.dart
@@ -4933,6 +4933,21 @@ class Bar extends Foo {
     verify([source]);
   }
 
+  void test_undefinedGetter_typeLiteral_conditionalAccess() {
+    // When applied to a type literal, the conditional access operator '?.' can
+    // be used to access instance getters of Type.
+    AnalysisOptionsImpl options = new AnalysisOptionsImpl();
+    options.enableNullAwareOperators = true;
+    resetWithOptions(options);
+    Source source = addSource('''
+class A {}
+f() => A?.hashCode;
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_undefinedGetter_typeSubstitution() {
     Source source = addSource(r'''
 class A<E> {
@@ -5008,6 +5023,21 @@ main() {
     // A call to verify(source) fails as '(() => null)()' isn't resolved.
   }
 
+  void test_undefinedMethod_typeLiteral_conditionalAccess() {
+    // When applied to a type literal, the conditional access operator '?.' can
+    // be used to access instance methods of Type.
+    AnalysisOptionsImpl options = new AnalysisOptionsImpl();
+    options.enableNullAwareOperators = true;
+    resetWithOptions(options);
+    Source source = addSource('''
+class A {}
+f() => A?.toString();
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_undefinedOperator_index() {
     Source source = addSource(r'''
 class A {