This reverts commit a72b2f88.

Reason for revert: Breaks https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/builds/7093

Original change's description:
> [arm] Restrict grouping pushes before a TailCall to registers only
> 
> We optimize parallel moves performed before a TailCall by grouping adjacent
> pushes. This way, we may use a single instruction to push multiple registers at
> once. However, we also have support for pushing immediates and stack slots for
> which the benefit is questionnable therefore this patch removes support for
> them.
> 
> Concerning immediate pushes, it looks like a mistake since we do not have
> support for this case in `AssembleMove` so this patch removes it. Furthermore,
> if we add a test for this case, we see that a `push ip` instruction is
> generated, effectively pushing whatever was in `ip` at the time instead of
> pushing a constant.
> 
> Concerning stack slot pushes, we generate a more or less equivalent sequence of
> instructions.
> 
> Finally, grouping floating point pushes is not used anywhere so this patch
> removes support for this also.
> 
> Bug: v8:6553
> Change-Id: I9b820d33361fc442dd813f66e1f96cda41009110
> Reviewed-on: https://chromium-review.googlesource.com/567191
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
> Cr-Commit-Position: refs/heads/master@{#46718}

TBR=danno@chromium.org,jarin@chromium.org,pierre.langlois@arm.com,bmeurer@chromium.org

Change-Id: Ib9db9e6e4f033aeea32741e04b1b884429acc800
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6553
Reviewed-on: https://chromium-review.googlesource.com/574908Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46719}