Update regenerator to v0.8.34, and remove recast and ast-types.

This version of Regenerator pegs recast to v0.10.18, which pegs ast-types
to v0.8.2, which contains special support for all Babel AST types:
https://github.com/benjamn/ast-types/blob/master/def/babel.js

This version of Regenerator also exports the ast-types module object that
it uses (as regenerator.types), so that consumers like Babel can refer to
the exact same copy of ast-types when necessary, rather than requiring
ast-types themselves. Why that was risky: #1958.

package.json

@@ -28,7 +28,6 @@
   },
   "dependencies": {
     "acorn-jsx": "^1.0.0",
-    "ast-types": "~0.7.0",
     "babel-plugin-constant-folding": "^1.0.1",
     "babel-plugin-dead-code-elimination": "^1.0.2",
     "babel-plugin-eval": "^1.0.1",
@@ -63,8 +62,7 @@
     "path-exists": "^1.0.0",
     "path-is-absolute": "^1.0.0",
     "private": "^0.1.6",
-    "recast": "0.10.16",
+    "regenerator": "0.8.34",
-    "regenerator": "0.8.32",
     "regexpu": "^1.1.2",
     "repeating": "^1.1.2",
     "resolve": "^1.1.6",

src/babel/patch.js

@@ -1,83 +1,7 @@
 import estraverse from "estraverse";
 import extend from "lodash/object/extend";
-import types from "ast-types";
 import * as t from "./types";
 
 // estraverse
 
 extend(estraverse.VisitorKeys, t.VISITOR_KEYS);
-
-// regenerator/ast-types
-
-var def = types.Type.def;
-var or  = types.Type.or;
-
-//def("File")
-//  .bases("Node")
-//  .build("program")
-//  .field("program", def("Program"));
-
-def("Noop");
-
-def("AssignmentPattern")
-  .bases("Pattern")
-  .build("left", "right")
-  .field("left", def("Pattern"))
-  .field("right", def("Expression"));
-
-def("RestElement")
-  .bases("Pattern")
-  .build("argument")
-  .field("argument", def("expression"));
-
-def("DoExpression")
-  .bases("Expression")
-  .build("body")
-  .field("body", [def("Statement")]);
-
-def("Super")
-  .bases("Expression");
-
-def("ExportDefaultDeclaration")
-  .bases("Declaration")
-  .build("declaration")
-  .field("declaration", or(
-    def("Declaration"),
-    def("Expression"),
-    null
-  ));
-
-def("ExportNamedDeclaration")
-  .bases("Declaration")
-  .build("declaration")
-  .field("declaration", or(
-    def("Declaration"),
-    def("Expression"),
-    null
-  ))
-  .field("specifiers", [or(
-    def("ExportSpecifier")
-  )])
-  .field("source", or(def("ModuleSpecifier"), null));
-
-def("ExportNamespaceSpecifier")
-  .bases("Specifier")
-  .field("exported", def("Identifier"));
-
-def("ExportDefaultSpecifier")
-  .bases("Specifier")
-  .field("exported", def("Identifier"));
-
-def("ExportAllDeclaration")
-  .bases("Declaration")
-  .build("exported", "source")
-  .field("exported", def("Identifier"))
-  .field("source", def("Literal"));
-
-def("BindExpression")
-  .bases("Expression")
-  .build("object", "callee")
-  .field("object", or(def("Expression"), null))
-  .field("callee", def("Expression"));
-
-types.finalize();

src/babel/transformation/transformers/other/regenerator.js

@@ -1,6 +1,11 @@
 import regenerator from "regenerator";
 import * as t from "../../../types";
-import { NodePath } from "ast-types";
+
+// It's important to use the exact same NodePath constructor that
+// Regenerator uses, rather than require("ast-types").NodePath, because
+// the version of ast-types that Babel knows about might be different from
+// the version that Regenerator depends on. See for example #1958.
+const NodePath = regenerator.types.NodePath;
 
 export var metadata = {
   group: "builtin-advanced"