Re-land of CL 2990703002, adding fixes to analyzer_test and error_test.

pkg/analyzer/lib/src/generated/error_verifier.dart

Index: pkg/analyzer/lib/src/generated/error_verifier.dart
diff --git a/pkg/analyzer/lib/src/generated/error_verifier.dart b/pkg/analyzer/lib/src/generated/error_verifier.dart
index 50513f74be7c9b4b34d9a864b80799d318001ad6..4660299dcd3ca2e7f282454ef644d7b559905ae6 100644
--- a/pkg/analyzer/lib/src/generated/error_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/error_verifier.dart
@@ -962,7 +962,6 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
         _checkForMismatchedAccessorTypes(node, methodName);
       }
       if (node.isGetter) {
-        _checkForVoidReturnType(node);
         _checkForConflictingStaticGetterAndInstanceSetter(node);
       } else if (node.isSetter) {
         _checkForInvalidModifierOnBody(
@@ -6040,19 +6039,6 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
 //        }
   }
 
-  /**
-   * Verify that the given [getter] does not have a return type of 'void'.
-   *
-   * See [StaticWarningCode.VOID_RETURN_FOR_GETTER].
-   */
-  void _checkForVoidReturnType(MethodDeclaration getter) {
-    TypeAnnotation returnType = getter.returnType;
-    if (returnType is TypeName && returnType.name.name == "void") {
-      _errorReporter.reportErrorForNode(
-          StaticWarningCode.VOID_RETURN_FOR_GETTER, returnType);
-    }
-  }
-
   /**
    * Verify the given operator-method [declaration], has correct number of
    * parameters.