* libc/machine/spu/impure.c: New file, supply a non-static _impure_data.
* libc/machine/spu/Makefile.am: Add new file impure.c.
* libc/machine/spu/Makefile.in: Regenerate.
* libc/machine/spu/sys/errno.h: Define errno to be _reent_data._errno.
* libc/machine/spu/sys/errno.h: New file, so spu errno values match
ppu linux values. This file is a copy of the cris/sys/errno.h plus
a few changes (see spu errno.h comments).