This is for the finch experiment CL 1592792 V8HugeMaxOldGenerationSize
(--js-flags="huge_max_old_generation_size").
The purpose of this finch is to support web apps that require more heap
space for their data sets.

The current max_old_space_size is 2 GB. This CL increases the size to 4 GB for
64-bit systems with a physical memory size bigger than 16 GB. This CL does not
change MaxGrowingFactor. HeapController::kMaxSize is still set to 2GB so the
GC schedule remains the same.

All tests from "tools\dev\gm.py x64.release.check" passes in my local machine
with FLAG_increase_max_old_space_size forced to true.

Bug:958974

Change-Id: I9d916d75c0b16342040dd1336e28e423e5bcc474
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1592129
Commit-Queue: Maggie Chen <magchen@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61297}