Runtime.queryObjects method:
1. force gc,
2. iterate through heap and get all objects with passed constructorName
   or with passed constructor name in prototype chain,
3. return these objects as JSArray.

Main use case is regression tests for memory leaks.

R=pfeldman@chromium.org,alph@chromium.org,ulan@chromium.org

Bug: v8:6732
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I52f0803366f14bb24376653615d870a4f21f83e7
Reviewed-on: https://chromium-review.googlesource.com/619594Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47478}