Runtime profiler uses bytecode array size for the tiering up decisions.
Bytecode array size includes the header size as well. Inlining
heuristics use bytecode array length instead. Bytecode array length
is just the size of bytecode not inlcuding any headers. This change
is to keep both of them in sync to avoid confusion. Also, the header
contains several pointers and hence the size changes depending on the
size of kPointerSize.

Bug: 
Change-Id: I22a9cf5e0bb9d6853c6a8be8d69c9ff459418a0d
Reviewed-on: https://chromium-review.googlesource.com/670724Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48081}