Now that all uses of LoadStackPointer have been removed, this CL cleans
up related code:

- Removed LoadStackPointer.
- Removed ArchStackPointer.
- Removed IA32StackCheck.
- Removed X64StackCheck.
- Removed StackCheckMatcher.

All stack checks now follow a simple path without matchers or special
register constraints: they load the limit and pass it to
StackPointerGreaterThan, which is finally handled by code generation.

Bug: v8:9534
Change-Id: Ib1d7be1502a471541d6441f3261aac0c949525fb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1748737
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63166}