Revert of [turbofan] Add alignment parameter to StackSlot operator (patchset #7 id:120001 of https://codereview.chromium.org/2816743003/ )

Reason for revert:
Seems to break cfi:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20cfi/builds/9989

Original issue's description:
> [turbofan] Add alignment parameter to StackSlot operator
>
> If alignment parameter is set, the memory returned by the
> StackSlot operator will be aligned according to the parameter.
>
> The implementation goes like this. If alignment parameter is set
> we allocate a bit more memory than actually needed and so we
> can move the beginning of the StackSlot in order to have it aligned.
>
>
> BUG=
>
> Review-Url: https://codereview.chromium.org/2816743003
> Cr-Commit-Position: refs/heads/master@{#45197}
> Committed: https://chromium.googlesource.com/v8/v8/+/d8bfdb7a998adadc56aa5705a5998e75ceae7675

TBR=ahaas@chromium.org,clemensh@chromium.org,titzer@chromium.org,bmeurer@chromium.org,ivica.bogosavljevic@imgtec.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2867403002
Cr-Commit-Position: refs/heads/master@{#45203}