(_aes_crypt): Moved increment of src into the

source_loop. Also fixed stop condition, the loop was run 5 times,
not 4, as it should.
(_aes_crypt): Use src directly when accessing the source data,
don't use %o5.
(_aes_crypt): Renamed variables in source_loop.
(_aes_crypt): Changed stop condition in source_loop to not depend
on i.
Finally reduced the source_loop to 16 instructions. Also increased
the alignment of the code to 16.

Rev: src/nettle/sparc/aes.asm:1.49