With this CL we use interrupt for pause in two cases:
- when we process Debugger.pause on interruption,
- when we would like to break as soon as possible after OOM.
In all other cases, e.g. for async step into we use break
on function call by calling StepIn debugger action.

In mentioned cases we should not actually use interrupt as well:
- Debugger.pause in this case scheduled using interrupt and we
  may just break right now without requesting another interrupt,
  unfortunately blink side is not ready,
- we should use more reliable way to break right after near OOM
  callback, otherwise we can get this callback, increase limit,
  request break on next interrupt, before interrupt get another
  huge memory allocation and crash.

There are couple advantages:
- we get much better break locations for async stepping
  (see inspector tests expectations),
- we can remove DEBUG_BREAK interruption
  (it should speedup blackboxing with async tasks, see
  removed todo in debug.cc for details)
- it is required preparation step for async step out,
  (see https://chromium-review.googlesource.com/c/v8/v8/+/1054618)

Bug: v8:7753
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iabd7627dbffa9a0eab1736064caf589d02591926
Reviewed-on: https://chromium-review.googlesource.com/1054155
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53439}