Fix TSAbstractClass base (#1676)

This lets the comment traversal code discover it

src/typescript-ast-nodes.js

@@ -179,7 +179,7 @@ module.exports = function(fork) {
 
   def("TSAbstractClassProperty").build("key", "value").bases("Node");
 
-  def("TSAbstractClassDeclaration").build().bases("Node");
+  def("TSAbstractClassDeclaration").build().bases("ClassDeclaration");
 
   def("TSInterfaceHeritage")
     .build("id", "typeParameters")

tests/typescript_comments/__snapshots__/jsfmt.spec.js.snap

@@ -1,5 +1,26 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`abstract_class.ts 1`] = `
+abstract class AbstractRule {
+    /**
+     * @deprecated
+     * Failures will be filtered based on \`tslint:disable\` comments by tslint.
+     * This method now does nothing.
+     */
+    filterFailures() {}
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+abstract class AbstractRule {
+  /**
+     * @deprecated
+     * Failures will be filtered based on \`tslint:disable\` comments by tslint.
+     * This method now does nothing.
+     */
+  filterFailures() {}
+}
+
+`;
+
 exports[`types.ts 1`] = `
 (() => {
   // swallow error and fallback to using directory as path

tests/typescript_comments/abstract_class.ts

@@ -0,0 +1,8 @@
+abstract class AbstractRule {
+    /**
+     * @deprecated
+     * Failures will be filtered based on `tslint:disable` comments by tslint.
+     * This method now does nothing.
+     */
+    filterFailures() {}
+}