[mythtv] [patch] mmx_gcc.cpp

[Daniel Thor Kristjansson]

This is a rewrite of the TDStretchMMX and FIRFilterMMX implementations 
in libmythsoundtouch. As per Issac's suggestion it uses intrinsics 
instead of volatile asm blocks. This allows the compiler more headroom 
for spilling registers, which means we no longer need special compile 
flags for libmythsoundtouch. Plus, I found a couple little optimizations.

BTW Who ever is responsible for the time stretch feature, I really like 
it. Both the speedup, for old ST:TNG's, and the slowdown, for foreign 
language news.

-- Daniel