PR fortran/32049

	* gfortran.h (gfc_real_info): Add c_float128 field.
	* mathbuiltins.def: Indicate which builtins are const.
	* trans-types.h (float128_type_node, complex_float128_type_node,
	gfc_real16_is_float128): New variables.
	* trans-types.c (float128_type_node, complex_float128_type_node,
	gfc_real16_is_float128): New variables.
	(gfc_init_kinds): Allow TFmode.
	(gfc_build_real_type): Mark __float128 types as such.
	(gfc_init_types): Initialize float128_type_node and
	complex_float128_type_node
	* f95-lang.c (gfc_init_builtin_functions): Adjust for new
	argument of OTHER_BUILTIN macro.
	* trans-intrinsic.c (gfc_intrinsic_map_t): Likewise.
	(builtin_decl_for_precision): Special case for __float128.
	(builtin_decl_for_float_kind): Likewise.
	(define_quad_builtin): New function.
	(gfc_build_intrinsic_lib_fndecls): Create all __float128
	library decls if necessary. Store them in the real16_decl and
	complex16_decl builtin map fields.
	(gfc_get_intrinsic_lib_fndecl): Handle q-suffixed __float128
	library function names.

	* gfortran.dg/random_seed_1.f90: Adjust test.
	* gfortran.dg/float128_1.f90: New test.

From-SVN: r163597