S128Load and S128Store are not used, we create a node with Load/Store
opcode and store the appropriate LoadType/StoreType indicating this is a
128-bit type.

Bug: v8:11384
Change-Id: Ida4a36ab893637525cb827b659753ac90fcca743
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2760539Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73413}