deprecate old transformer names

lib/6to5/transformation/transform.js

@@ -25,7 +25,15 @@ transform.fromAst = function (ast, code, opts) {
 transform._ensureTransformerNames = function (type, keys) {
   for (var i = 0; i < keys.length; i++) {
     var key = keys[i];
-    if (!transform.transformers[key]) {
+
+    var newKey = transform.deprecatedTransformerMap[key];
+    if (newKey) {
+      console.error(
+        "The transformer " + key + " has been renamed to " + newKey +
+        " in v3.0.0 - backwards compatibilty will be removed 4.0.0"
+      );
+      keys[i] = newKey;
+    } else if (!transform.transformers[key]) {
       throw new ReferenceError(
         "Unknown transformer " + key + " specified in " + type + " - " +
         "transformer key names have been changed in 3.0.0 see " +
@@ -36,6 +44,45 @@ transform._ensureTransformerNames = function (type, keys) {
   }
 };
 
+transform.deprecatedTransformerMap = {
+  specNoForInOfAssignment: "validation.noForInOfAssignment",
+  specSetters: "validation.setters",
+  specBlockScopedFunctions: "spec.blockScopedFunctions",
+  malletOperator: "playground.malletOperator",
+  methodBinding: "playground.methodBinding",
+  memoizationOperator: "playground.memoizationOperator",
+  objectGetterMemoization: "playground.objectGetterMemoization",
+  modules: "es6.modules",
+  propertyNameShorthand: "es6.properties.shorthand",
+  arrayComprehension: "es7.comprehensions",
+  generatorComprehension: "es7.comprehensions",
+  arrowFunctions: "es6.arrowFunctions",
+  classes: "es6.classes",
+  objectSpread: "es7.objectSpread",
+  exponentiationOperator: "es7.exponentiationOperator",
+  spread: "es6.spread",
+  templateLiterals: "es6.templateLiterals",
+  propertyMethodAssignment: "es6.properties.shorthand",
+  computedPropertyNames: "es6.properties.computed",
+  defaultParameters: "es6.parameters.default",
+  restParameters: "es6.parameters.rest",
+  destructuring: "es6.destructuring",
+  forOf: "es6.forOf",
+  unicodeRegex: "es6.unicodeRegex",
+  abstractReferences: "es7.abstractReferences",
+  constants: "es6.constants",
+  letScoping: "es6.letScoping",
+  blockScopingTDZ: "es6.blockScopingTDZ",
+  generators: "regenerator",
+  protoToAssign: "spec.protoToAssign",
+  typeofSymbol: "spec.typeofSymbol",
+  coreAliasing: "selfContained",
+  undefinedToVoid: "spec.undefinedToVoid",
+  undeclaredVariableCheck: "validation.undeclaredVariableCheck",
+  specPropertyLiterals: "minification.propertyLiterals",
+  specMemberExpressionLiterals: "minification.memberExpressionLiterals",
+};
+
 transform.transformers = object();
 
 transform.moduleFormatters = {