c: Add u{,l,ll,imax}abs builtins [PR117024]

The following patch adds u{,l,ll,imax}abs builtins, which just fold
to ABSU_EXPR, similarly to how {,l,ll,imax}abs builtins fold to
ABS_EXPR.

2024-11-21  Jakub Jelinek  <jakub@redhat.com>

	PR c/117024
gcc/
	* coretypes.h (enum function_class): Add function_c2y_misc
	enumerator.
	* builtin-types.def (BT_FN_UINTMAX_INTMAX, BT_FN_ULONG_LONG,
	BT_FN_ULONGLONG_LONGLONG): New DEF_FUNCTION_TYPE_1s.
	* builtins.def (DEF_C2Y_BUILTIN): Define.
	(BUILT_IN_UABS, BUILT_IN_UIMAXABS, BUILT_IN_ULABS,
	BUILT_IN_ULLABS): New builtins.
	* builtins.cc (fold_builtin_abs): Handle also folding of u*abs
	to ABSU_EXPR.
	(fold_builtin_1): Handle BUILT_IN_U{,L,LL,IMAX}ABS.
gcc/lto/ChangeLog:
	* lto-lang.cc (flag_isoc2y): New variable.
gcc/ada/ChangeLog:
	* gcc-interface/utils.cc (flag_isoc2y): New variable.
gcc/testsuite/
	* gcc.c-torture/execute/builtins/lib/abs.c (uintmax_t): New typedef.
	(uabs, ulabs, ullabs, uimaxabs): New functions.
	* gcc.c-torture/execute/builtins/uabs-1.c: New test.
	* gcc.c-torture/execute/builtins/uabs-1.x: New file.
	* gcc.c-torture/execute/builtins/uabs-1-lib.c: New file.
	* gcc.c-torture/execute/builtins/uabs-2.c: New test.
	* gcc.c-torture/execute/builtins/uabs-2.x: New file.
	* gcc.c-torture/execute/builtins/uabs-2-lib.c: New file.
	* gcc.c-torture/execute/builtins/uabs-3.c: New test.
	* gcc.c-torture/execute/builtins/uabs-3.x: New test.
	* gcc.c-torture/execute/builtins/uabs-3-lib.c: New test.