Add a dex structure definition to support exception handling.
Add a dex structure definition to support exception handling.

Change-Id: I586773e1526c6ade46a74251cb838cab74d7de7a

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