- Move the check from the BytecodeArrayBuilder destructor, which doesn't get
  called, to the ToBytecodeArray function.
- Remove the now empty destructor.
- For generators, bind unused resume point labels somewhere.

R=rmcilroy@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/1924093005
Cr-Commit-Position: refs/heads/master@{#35862}