If DecodeLocals exits early, num_locals_ is left in an inconsistent
state. This CL fixes this issue by updating num_locals_ as the
local_types_ are updated.

Bug: chromium:1154439
Change-Id: I02328a050df8b2827a42f59443e994f535d3c826
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567954Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71566}