Instead of having one decoder method per opcode, make all load and store
opcodes use the same method, and load the necessary information from a
static array.

R=thibaudm@chromium.org

Bug: v8:10576
Change-Id: I27daf52b9cb0af6a288a5642913c132e20f0eabd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2287489Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68740}