Even better stack chains with VM async/await.

It turns out the VM can generate frames that have the previous
method's name in the <..._async_body> member.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//936643002
5 files changed
tree: 4fc1b88fa061f0ec5421650fbae23e95088d6317
  1. pkgs/