Port fb28cfe6

Original Commit Message:

    So far, discarded size was maintained by the sweeper but not wired up
    anywere.

    Changes in this patch:
    - Wire up resident size in heap statistics collection.
    - Fix bugs in reporting committed and resident size.
    - Sweeper test: Enforce some internal details. The details should not
      not be checked broadly but be kept as a detail to the sweeper
      itself.
    - Stats collection: Test that committed and resident set size are
      reported and differ after discarding GCs.

R=mlippautz@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: I19be251596ccc955f5c4cd43a46e566001a36ac4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3021468Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75688}