Add cold versions of benchmarks.

- Created macros for one and two buffer benchmarks to simplify
  addition of new benchmarks.
- Created cold versions of all benchmarks that work on buffer benchmarks.
  This means that the benchmark is given buffers that are not in the cache.
- Verified the cold versions are working as intended by
  changing it so that the same buffer is written in each loop
  instead of the strided buffer. Using this method, the cold and
  normal benchmark run at the same speed.

Merge from internal master.

(cherry-picked from 991bcd464d67c3cff76477140331619ff138aafc)

Change-Id: I4b1b55510d90cc9a941fd68244971cb08cfba553
Merge "Add cold versions of benchmarks."
am 5b1efce4: Merge "Add cold versions of benchmarks."

* commit '5b1efce4aeea83c7b18dfed5d3366d6b84874c23':
  Add cold versions of benchmarks.
ext4_utils: Yet another MMC discard pain in the ass

 * Secure discard on this device is painfully slow. Use regular
   discard until the issue is sorted out.

Change-Id: Id6cc80ea7a25410b812803425a4b6267289834fb
Merge tag 'android-4.4.1_r1' into somex-4.4

Android 4.4.1 Release 1