This removes paired single (used on the 750CL and friends).  It was
deprecated in GCC 8.  Removing it means we only have one vector model
to deal with (VMX+VSX, 16-byte vectors).


	* config.gcc (powerpc*-*-*): Remove paired.h.  Unsupport the
	powerpc*-*-linux*paired* target.
	* config/rs6000/750cl.h: Delete.
	* config/rs6000/paired.h: Delete.
	* config/rs6000/paired.md: Delete.
	* config/rs6000/predicates.md (easy_vector_constant): Remove paired
	float support.
	* config/rs6000/rs6000-builtin.def: Remove paired float support.
	* config/rs6000/rs6000-c.c (rs6000_target_modify_macros): Update
	comment.  Remove paired float support.
	* config/rs6000/rs6000-modes.def: Remove V2SF and V2SI.
	* config/rs6000/rs6000-opts.h (enum rs6000_vector): Delete
	VECTOR_PAIRED.
	* config/rs6000/rs6000-protos.h (paired_expand_vector_init,
	paired_emit_vector_cond_expr, paired_expand_vector_move): Delete
	declarations.
	* config/rs6000/rs6000.c: Remove paired float support.
	(paired_expand_vector_init, paired_expand_vector_move,
	paired_emit_vector_compare, paired_emit_vector_cond_expr,
	(paired_expand_lv_builtin, paired_expand_stv_builtin,
	paired_expand_builtin, paired_expand_predicate_builtin,
	paired_init_builtins): Delete.
	* config/rs6000/rs6000.h: Remove paired float support.
	* config/rs6000/rs6000.md: Remove paired float support.
	(move_from_CR_ov_bit): Delete.
	* config/rs6000/rs6000.opt (mpaired): Delete.
	* config/rs6000/t-rs6000: Remove paired.md from MD_INCLUDES.
	* doc/invoke.texi (RS/6000 and PowerPC Options): Delete -mpaired.

From-SVN: r259833