Fix apps with more than one dex file with the same name

Reverts most of 60836d5a9bcf8b30984aae4279a4f6233b0bf622 which I
believe was an incorrect attempt to address issue introduced in
8d31bbd3d6536de12bc20e3d29cfe03fe848f9da, which is also reverted here.

Also adds some debugging aids include operator<< for DexFile and
MemMap and checksum information to OatFile logging.

Bug: 12802375
Change-Id: Idd6f7dd487f6e01e9479cd15cd4b61580160e8a3
6 files changed