Fix portable sign/zero extension from JNI.
Fix portable sign/zero extension from JNI.

Change-Id: I115aee9207105225f20fb105072f7d8ac41eac21

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst