Revert of "[heap] Divide available memory upon compaction tasks" (patchset #5 id:90008 of https://codereview.chromium.org/1415733004/ )

Reason for revert:
Failing again: http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/2183

Original issue's description:
> Reland of "[heap] Divide available memory upon compaction tasks"
>
> This reverts commit cf71c28f.
>
> Original message:
>
> [heap] Divide available memory upon compaction tasks
> - Fairly (round-robin) divide available memory upon compaction tasks.
> - Ensure an upper limit (of memory) since dividing is O(n) for n free-space
>   nodes.
> - Refill from free lists managed by sweeper once a compaction space becomes
>   empty.
>
> Assumption for dividing memory: Memory in the free lists is sparse upon starting
> compaction (which means that only few nodes are available), except for memory
> reducer GCs, which happen in idle time though (so it's less of a problem).
>
> BUG=chromium:524425
> LOG=N
>
> Committed: https://crrev.com/63f42ecb965d04877f45043c1416170b6f79b962
> Cr-Commit-Position: refs/heads/master@{#31436}

TBR=hpayer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:524425

Review URL: https://codereview.chromium.org/1405273003

Cr-Commit-Position: refs/heads/master@{#31439}