tree d1b5b74777c5a472316296ae9ab4b9c7fca3cc00
parent 466b6884dc4edeefd58e719fd4d31dddd9c0242e
author Alexander Aprelev <aam@google.com> 1553298411 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1553298411 +0000

[vm] Free readonly header bit so it can be used for other uses.

This is reland of https://dart-review.googlesource.com/c/sdk/+/97340 rebased on top of removal of GraphMarked bit, which was not compatible with this ReadOnly->InVMIsolateHeap change(due to how write-pages are not covered by Contains check)

Change-Id: I34c6421afb4baeafa5a449787020dab9fa800d05
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/97545
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>