Use logical shifts to emulate arithmetic shift, by first adding a bias
to make all signed values unsigned, then subtracting the shifted bias.
Details are in code comments for SharedTurboAssembler::I64x2ShrS.

Also refactor ia32 (which was already using this algorithm) to use the
shared macro-assembler function. And convert Liftoff's implementation as
well.

Bug: v8:12058
Change-Id: Ia1fd5fe5a9a0b7a7f31c426d4112256c8bf7021b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3083291
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76209}