Remove all uses of GetIsolate/GetHeap by passing Isolate in from all
call sites.

Bug: v8:7786
Change-Id: I64ff8d5796db9d602e86bff4d0b9297cbe700d0d
Reviewed-on: https://chromium-review.googlesource.com/1080819Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53467}