Besides, fix an error in set_if_nan, because if src is a NaN, we should
set the i32 instead of i64 at address dst to a non-zero value.

Port e6961df2

Bug: v8:11856

Change-Id: Icc9afda35d4cca4fd5ae82356ecaec77bf92d009
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3139055Reviewed-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/main@{#76636}