Vectorize bitmap operations on Krait and A15:

Caching some pre-scaled Bitmap objects allows for optimizing later
scaling operations to reduce memory pressure

Enable gcc vectorizing optimizations for Bitmap operations within
libandroid_runtime.so.  Adds -ftree-vectorize -mvectorize-with-neon-quad
-fprefetch-loop-arrays to functions and compiles Bitmap.cpp in ARM mode
(necessary to enable vectorizing optimizations) for appropriate targets

author is Lucas Crowthers<lucasc@codeaurora.org>
and
Steve Kondik<shade@chemlab.org>

Change-Id: Ic0528f24931f89b6d1ef60f45940c0b0812e4629
Merge "Vectorize bitmap operations on Krait and A15:" into jb4.2