Replace REAL_VALUES_LESS with real_less

Replace REAL_VALUES_LESS with real_less

This patch continues the removal of real-related macros by
replacing REAL_VALUES_LESS with real_less.

Bootstrapped & regression-tested on x86_64-linux-gnu.  Also tested by
building one target per CPU directory and checking that there were
no new warnings and no changes in testsuite output at -O2.

gcc/ada/
	* gcc-interface/trans.c (convert_with_check): Use real_less instead
	of REAL_VALUES_LESS.

gcc/
	* doc/tm.texi.in (REAL_VALUES_LESS): Delete.
	* doc/tm.texi: Regenerate.
	* real.h (real_less): Declare.
	(REAL_VALUES_LESS): Delete.
	* real.c (real_less): New function.
	(real_compare): Use it.
	* config/m68k/m68k.c (floating_exact_log2): Use real_less instead
	of REAL_VALUES_LESS.
	* config/microblaze/microblaze.c (microblaze_const_double_ok):
	Likewise.
	* fold-const.c (fold_convert_const_int_from_real): Likewise.
	* simplify-rtx.c (simplify_const_unary_operation): Likewise.
	(simplify_const_relational_operation): Likewise.
	* tree-call-cdce.c (check_pow): Likewise.
	(gen_conditions_for_pow_cst_base): Likewise.

From-SVN: r228475