Shuffles have pattern matching clauses which, depending on the
instruction used, can require src0 or src1 to be register or not.
However we do not have 16-byte alignment for SIMD operands yet, so it
will segfault when we use an SSE SIMD instruction with unaligned
operands.

This patch fixes all the shuffle cases to always use a register for the
input nodes, and it does so by ignoring the values of src0_needs_reg and
src1_needs_reg. When we eventually have memory alignment, we can
re-enable this check, without mucking around too much in the logic in
each shuffle match clause.

Bug: v8:9198
Change-Id: I264e136f017353019f19954c62c88206f7b90656
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2504849Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70848}