rs6000: Remove paired single

rs6000: Remove paired single

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