This disables the following features for --enable-third-party-heap:
- inline allocation: all allocation are directed to runtime for now
  until we have support for TPH inline allocation.
- allocation site pretenuring: this feature relies on ephemeral
  memento objects placed after ordinary objects and is tightly coupled
  with V8's GC.
- allocation folding in TurboFan: this feature assumes that objects
  of different size and type can be allocated on the same page using
  bump-pointer allocation.

Bug: v8:9533
Change-Id: Idbdf1dac566f37db379e5d4b43e0741886f4e69b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2463004
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70468}