If the function is not inlined, an immmediate cannot be used for the
shift parameter, so the %cl register must be used instead in that case.
This fixes compilation for x86-32 using gcc with --disable-optimizations.
This fixes unexpected name collisions that were occurring with variables
declared within the macros.
It also fixes the fate-acodec-ac3_fixed regression test on x86-32.
It contains optimizations that are not specific to i386 and
libavutil uses this naming scheme already.
Originally committed as revision 16270 to svn://svn.ffmpeg.org/ffmpeg/trunk
