Emit bit manipulation instructions for x86 and x86_64

This patch performs instruction simplification to
generate instructions andn, blsmsk and blsr on
cpus that have avx2.

Test: test.py --host --64, test-art-host-gtest
Change-Id: Ie41a1b99ac2980f1e9f6a831a7d639bc3e248f0f
Signed-off-by: Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com>