Delete powerpcspe

Delete powerpcspe

This deletes powerpcspe, which was deprecated for GCC 8.

This does not change the testsuite, or libgcc for rs6000 (which still
is shared code with powerpcspe, so can use some cleanup after this).

/
	* contrib/config-list.mk: Remove powerpc-eabispe and powerpc-linux_spe.

gcc/
	* config.gcc (Obsolete configurations): Delete powerpc*-*-*spe*.
	(Unsupported targets): Add powerpc*-*-*spe*.
	(powerpc*-*-*spe*): Delete.
	(powerpc-*-eabispe*): Delete.
	(powerpc-*-rtems*spe*): Delete.
	(powerpc*-*-linux*spe*): Delete.
	(powerpc*-*-linux*): Do not handle the linux*spe* targets.
	(powerpc-wrs-vxworks*spe): Delete.
	(with_cpu setting code): Delete powerpc*-*-*spe* handling.
	* config.host (target powerpc*-*-*spe*): Delete.
	* doc/invoke.texi (PowerPC SPE Options): Delete.
	(PowerPC SPE Options): Delete.
	* config/powerpcspe: Delete.

From-SVN: r266961