v128.const was incorrectly always lowered to 4 word32 nodes, regardless
of what the lowered type was set to be.

In the test case, v128.const was consumed by i8x16.eq, so the lowered
typed of v128.const node was set to SimdType::kInt8x16, but it was still
lowered as a SimdType::kInt32x4, and then later crashes when lowering
the comparisons.

Bug: v8:10507
Change-Id: I24f16c94968cd8b6c7cd5d400d1a0046da3d47da
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2391919
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69755}