Besides, fix i64x2 widen i32x4 instructions in mips32.

Change-Id: I85e3f8f4ab16c268a5b17189f67c78ef45762e39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2711737Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Auto-Submit: Liu yu <liuyu@loongson.cn>
Cr-Commit-Position: refs/heads/master@{#72907}