Fix dalvik-dev build. Handle the case of no input dex.
Fix dalvik-dev build. Handle the case of no input dex.

(cherry picked from commit a5dd6bef562dd5bafdf84eb0f0a00703218f97b6)

Change-Id: Ia003c972ead98d0affb32f13142ef2d3ba178857

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