This is done with a script that does something like:

files=$(ag 'v\d\d?x\d\d?[._]?all_?true' -l)
sed -i 's/V\(8x16\|16x8\|32x4\|64x2\)\([._]\?\)\([aA]ll_\?[tT]rue\)/I\1\2\3/g' $(files)
sed -i 's/v\(8x16\|16x8\|32x4\|64x2\)\([._]\?\)\([aA]ll_\?[tT]rue\)/i\1\2\3/g' $(files)

And manual fixups in test-run-wasm-simd.cc and wasm-opcodes-inl.h.

Bug: v8:10946
Change-Id: Ib5dad388dd6dd9cd0fb575ad961dffc189a2e6ef
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2740488Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73309}