This allows expressions like:
(x + y) & -1
[intish] & [signed]

The previous conversion condition was too strict (intended to
forbid non-int expression conversion). Expressing in
a different way.

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/1717213002

Cr-Commit-Position: refs/heads/master@{#34228}