add eval optional transformer

src/babel/transformation/transformers/index.js

@@ -4,6 +4,7 @@ export default {
 
   //- builtin-setup
   strict:                                  require("./other/strict"),
+  eval:                                    require("./other/eval"),
   _explode:                                require("./internal/explode"),
   _validation:                             require("./internal/validation"),
   _hoistDirectives:                        require("./internal/hoist-directives"),

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

@@ -0,0 +1,22 @@
+import traverse from "../../../traversal";
+import parse from "../../../helpers/parse";
+import * as t from "../../../types";
+
+export var metadata = {
+  group: "builtin-pre",
+  optional: true
+};
+
+export function CallExpression(node) {
+  if (this.get("callee").isIdentifier({ name: "eval" }) && node.arguments.length === 1) {
+    var evaluate = this.get("arguments")[0].evaluate();
+    if (!evaluate.confident) return;
+
+    var code = evaluate.value;
+    if (typeof code !== "string") return;
+
+    var ast = parse(code);
+    traverse.removeProperties(ast);
+    return ast.program;
+  }
+}