to get rid of the pattern
```
EnsureHash();
uint32_t field = raw_hash_field();
```
which requires an additional load and might be misleading in the
presence of forwarding indices for shared strings, as raw_hash_field()
can return a forwarding index, whereas EnsureRawHash() will always
return a computed hash value.

Bug: v8:12957
Change-Id: I33426fef433f774fb323d4381e784c1037fb6fbb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3829469Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82441}