Work around for android full debug build runnign out of registers.
5 functions were running out of registers causing the compiler error
error: 'asm' operand has impossible constraints
These functions mostly have 4 pointers, a counter (width) and a tempory
eax register.  With fpic and debug using stackframes, 2 registers are
unavailable.  So a total of 8 registers are used.
Although fpic and stack frame dont apply to assembly, the compiler
reserves 2 registers.  The optimized version builds, so its likely
freeing up the registers once it knows they are not used.
These functions used to build, so compile options and/or compiler may
have updated.. likely fpic was turned on.
An attribute can be done to disable each, and will avoid using the
2 GPR registers, but they are still reserved and unavailable in debug
builds on current compilers (gcc 4.9 and clang 3.8).

R=dhrosa@google.com
BUG=libyuv:602

Review URL: https://codereview.chromium.org/2066933002 .