This reverts commit 66129430.

Reason for revert: Fails on gcc: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20gcc/3394

Original change's description:
> [regexp] Bytecode peephole optimization
> 
> Bytecodes used by the regular expression interpreter often occur in
> specific sequences. The number of dispatches in the interpreter can be
> reduced if those sequences are combined into a single bytecode.
> 
> This CL adds a peephole optimization pass for regexp bytecodes.
> This pass checks the generated bytecode for pre-defined sequences that
> can be merged into a single bytecode.
> 
> With the currently implemented bytecode sequences a speedup of 1.12x on
> regex-dna and octane-regexp is achieved.
> 
> Bug: v8:9330
> Change-Id: I827f93273a5848e5963c7e3329daeb898995d151
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1813743
> Commit-Queue: Patrick Thier <pthier@google.com>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63992}

TBR=jgruber@chromium.org,petermarshall@chromium.org,pthier@google.com

Change-Id: Ie526fe3691f6abdd16b51979000fdafb7afce8ef
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9330
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1826727Reviewed-by: Clemens Backes [né Hammacher] <clemensb@chromium.org>
Commit-Queue: Clemens Backes [né Hammacher] <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63998}