When we try to further fold previously folded allocations in Crankshaft
GVN we don't properly transform the allocations involved, which causes
the mechanism to leave holes in the new/old space (and thereby violate
the iterability property of the new/old space).

BUG=chromium:621868
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2297983003
Cr-Commit-Position: refs/heads/master@{#39040}