4 instructions, int32x4.trunc_f32x4_{s,u},
int32x4.trunc_f64x2_{s,u}_zero.

ia32 port of a7b208739d2dabe11ca4e792085aed3455e879d5.

Bug: v8:12284
Change-Id: Ia94ff572b63f9fd8e3bfe2dd8e5fa41212f84a76
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3255661Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77807}