Save/restore only live registers in the generator suspend/resume.

test/mjsunit/harmony/regress-generators-resume.js

Index: test/mjsunit/harmony/regress-generators-resume.js
diff --git a/test/mjsunit/harmony/regress-generators-resume.js b/test/mjsunit/harmony/regress-generators-resume.js
new file mode 100644
index 0000000000000000000000000000000000000000..c72ac30b483250fda41c25d11542aeffbcd8303e
--- /dev/null
+++ b/test/mjsunit/harmony/regress-generators-resume.js
@@ -0,0 +1,18 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+
+function* foo() {
+  for (let i = 0; i < 10; i++) {
+    yield 1;
+  }
+  return 0;
+}
+
+g = foo();
+%OptimizeFunctionOnNextCall(foo);
+g.next();
+g.next();