This reverts commit 7ef1df85.

Reason for revert: Breaks inspector/debugger/get-possible-breakpoints-restrict-to-function: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap%20-%20debug/builds/13191/steps/Check/logs/get-possible-breakpoi..

Original change's description:
> [builtins] port Promise.all to CSA
> 
> Introduces CodeStubAssembler helpers for common Iterator operations
> (GetIterator, IteratorStep, IteratorClose).
> 
> Moves the Promise.all resolveElement closure and it's caller to
> builtins-promise-gen.cc.
> 
> Instead of creating an internal array (and copying its elements into a result
> array), a single JSArray is allocated, and appended with BuildAppendJSArray(),
> falling back to %CreateDataProperty(), and elements are updated in the resolve
> closure the same way. This should always be unobservable.
> 
> This CL increases the size of snapshot_blob.bin on an x64.debug build by 11.44kb
> 
> BUG=v8:5343
> R=​cbruni@chromium.org, gsathysa@chromium.org, jgruber@chromium.org
> 
> Change-Id: Id69b7f76866b29caccd97f35870154c4be85f418
> Reviewed-on: https://chromium-review.googlesource.com/497974
> Commit-Queue: Caitlin Potter <caitp@igalia.com>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45306}

TBR=adamk@chromium.org,cbruni@chromium.org,gsathya@chromium.org,caitp@igalia.com,jgruber@chromium.org,ishell@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5343

Change-Id: I831738003643561fa628266af2bcebbb18000e55
Reviewed-on: https://chromium-review.googlesource.com/506014Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45313}