force default parameter IIFE on reference to eval

src/babel/transformation/transformers/es6/parameters.default.js

@@ -12,8 +12,10 @@ var hasDefaults = function (node) {
 
 var iifeVisitor = {
   ReferencedIdentifier(node, parent, scope, state) {
-    if (!state.scope.hasOwnBinding(node.name)) return;
-    if (state.scope.bindingIdentifierEquals(node.name, node)) return;
+    if (node.name !== "eval") {
+      if (!state.scope.hasOwnBinding(node.name)) return;
+      if (state.scope.bindingIdentifierEquals(node.name, node)) return;
+    }
 
     state.iife = true;
     this.stop();

test/core/fixtures/transformation/es6.parameters.default/eval/actual.js

@@ -0,0 +1,6 @@
+let x = "outside";
+function outer(a = () => eval("x")) {
+  let x = "inside";
+  return a();
+}
+outer();

test/core/fixtures/transformation/es6.parameters.default/eval/expected.js

@@ -0,0 +1,13 @@
+"use strict";
+
+var x = "outside";
+function outer() {
+  var a = arguments[0] === undefined ? function () {
+    return eval("x");
+  } : arguments[0];
+  return (function () {
+    var x = "inside";
+    return a();
+  })();
+}
+outer();