Add support for creating types in JSTypeNative and JSTypes needed for

Es6RewriteGenerators.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=165596038

src/com/google/javascript/jscomp/newtypes/JSTypes.java

@@ -471,6 +471,10 @@ public JSType getNativeType(JSTypeNative typeId) {
         return UNDEFINED;
       case NULL_TYPE:
         return NULL;
+      case FALSE_TYPE:
+        return FALSE_TYPE;
+      case TRUE_TYPE:
+        return TRUE_TYPE;
       case BOOLEAN_TYPE:
         return BOOLEAN;
       case STRING_TYPE:
@@ -510,6 +514,8 @@ public JSType getNativeType(JSTypeNative typeId) {
         return getITemplateArrayType();
       case ITERATOR_TYPE:
         return getIteratorInstance(UNKNOWN);
+      case GENERATOR_TYPE:
+        return getGeneratorInstance(UNKNOWN);
       default:
         throw new RuntimeException("Native type " + typeId.name() + " not found");
     }

src/com/google/javascript/rhino/jstype/JSTypeNative.java

@@ -81,16 +81,22 @@ public enum JSTypeNative {
   DATE_TYPE,
   DATE_FUNCTION_TYPE,
 
+  EMPTY_OBJECT_LITERAL_TYPE,
+
   ERROR_FUNCTION_TYPE,
   ERROR_TYPE,
 
   EVAL_ERROR_FUNCTION_TYPE,
   EVAL_ERROR_TYPE,
 
+  FALSE_TYPE,
+
   FUNCTION_FUNCTION_TYPE,
   FUNCTION_INSTANCE_TYPE, // equivalent to U2U_CONSTRUCTOR_TYPE
   FUNCTION_PROTOTYPE,
 
+  GENERATOR_TYPE,
+
   I_ITERABLE_RESULT_TYPE,
   ITERATOR_TYPE,
 
@@ -105,7 +111,6 @@ public enum JSTypeNative {
   OBJECT_TYPE,
   OBJECT_FUNCTION_TYPE,
   OBJECT_PROTOTYPE,
-  EMPTY_OBJECT_LITERAL_TYPE,
 
   RANGE_ERROR_FUNCTION_TYPE,
   RANGE_ERROR_TYPE,
@@ -123,6 +128,8 @@ public enum JSTypeNative {
   SYNTAX_ERROR_FUNCTION_TYPE,
   SYNTAX_ERROR_TYPE,
 
+  TRUE_TYPE,
+
   TYPE_ERROR_FUNCTION_TYPE,
   TYPE_ERROR_TYPE,