We previously supported use of bitwise operations to convert
from intish to int, but use of kAsmInt in some places and kAsmIntQ
in others prevents this from working with heap accesses.
Switch to use kAsmIntQ where appropriate (even though intish_ != 0
in principle captures the superset of these cases),
as it's more conservative (and uses types.h better).

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=mjsunit/asm-wasm
R=aseemgarg@chromium.org,titzer@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1731603002

Cr-Commit-Position: refs/heads/master@{#34233}