fold-const.c (fold_abs_const): Make extern.

fold-const.c (fold_abs_const): Make extern.

	* fold-const.c (fold_abs_const): Make extern.
	* tree.h (fold_abs_const): Prototype here.
	* builtins.c (fold_builtin_fabs): New function to transform
	fabs, fabsf and fabsl builtins into ABS_EXPR tree nodes.
	(fold_builtin_abs): New function to transform abs, labs, llabs
	and imaxabs builtins into ABS_EXPR tree nodes.
	(expand_builtin): Fall back to a function call for abs, labs,
	llabs and imaxabs builtins that survive constant folding.
	(fold_builtin_1): Call fold_builtin_fabs for FABS, FABSF and
	FABSL, and fold_builtin_abs for ABS, LABS, LLABS and IMAXABS.

From-SVN: r82916