memcheck: Remove feature entirely

This patch removes the memcheck feature from the Android emulator
code base. This is for several reasons:

- Supporting the feature impacts many QEMU-specific emulation files
  in subtle ways, that make it difficult to refactor this code to
  integrate upstream changes.

- The feature only works for ARM (32-bit), has no unit tests, and
  generates massive amounts of false positive messages coming
  from the platform.

- Barely anyone uses it.

This feature might make a comeback in the future, but this will be
under a different life-form that will have adapted to the new state
of the code.

+ As a bonus, fix the build!

Change-Id: Idd19a3bc7923379cb1e82850f14499549b6a991b
56 files changed