c99_protos.h: Add prototypes for C99 complex functions.

	* c99_protos.h: Add prototypes for C99 complex functions.
	* libgfortran.h: Include complex.h before c99_protos.h.
	* intrinsics/c99_functions.c: Define HAVE_ macros for the
	fallback functions we provide.
	(cabsf, cabs, cabsl, cargf, carg, cargl, cexpf, cexp, cexpl,
	clogf, clog, clogl, clog10f, clog10, clog10l, cpowf, cpow, cpowl,
	cqsrtf, csqrt, csqrtl, csinhf, csinh, csinhl, ccoshf, ccosh,
	ccoshl, ctanhf, ctanh, ctanhl, csinf, csin, csinl, ccosf, ccos,
	ccosl, ctanf, ctan, ctanl): New fallback functions.
	* Makefile.am (gfor_math_trig_c, gfor_math_trig_obj,
	gfor_specific_c, gfor_cmath_src, gfor_cmath_obj): Remove.
	* Makefile.in: Regenerate.
	* configure.ac: Remove checks for csin. Add checks for all C99
	complex functions.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* aclocal.m4: Regenerate.

From-SVN: r104626