Track package manager changes for arch specific dexopt.

- Changes signature of isDexOptNeededInternal. No behavioural
  changes are needed because dalvik only uses the first argument
  to the function (the "name") and dexopt is architecture agnostic.

- Changes dexOptGenerateCacheFileName to place dex files under
  /data/dalvik-cache/<instruction-set>. This allows us to avoid
  needing dalvik specific logic in the package manager and installd.

(cherry picked from commit f752d041dac2cc8e26d03292ffec986a2bf905f9)

Change-Id: Ie31c9925269d6ac97d358ce49219557692704329
Merge "Track package manager changes for arch specific dexopt."
Define kInstructionSet for x86-64 and arm64.

This fixes 64-bit host compilation of libdex.

Change-Id: I364b624e12620f844cc7bbaa08e679c8a529f87c
Merge "Define kInstructionSet for x86-64 and arm64."
auto-merger: merge in from aosp/master