* Fix 32 and 16 bit register store in YJIT

Co-Authored-By: Takashi Kokubun <takashikkbn@gmail.com>

* Remove an unnecessary diff

* Reuse an rm_num_bits result

* Use u16::MAX instead

* Update the link

Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>

* Just use sturh for 16 bits

Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>