This fixes the order of declaring class members for LiftoffCompiler,
LiftoffAssembler, LiftoffRegister, and LiftoffRegList.
The recommended order according to the style guide is: types, constants,
constructors, other members, data members.

R=thibaudm@chromium.org

Bug: v8:11879
Change-Id: I5c550ed11ed0169f07477b6a1723053316374707
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3157960
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76798}