This patch simply wraps the following define with #ifdef __GNUC__ as follows
#define ALLOW OPTIMIZATIONS 1
Since the optimizations only compile with the GCC compiler, this fix allows you to build audacity without optimizations when building with other compilers, such as Sun Studio.
Note the patch also removes all the ^M characters from lib-src/soundtouch/soundtouch/STTypes.h file.
At some future date it might be good to fix the optimization code so it also builds with Sun Studio (perhaps via using mediaLib), but that can be done later.