sys/wait.h: add WCOREDUMP as alternative to WIFCORED

As this is part of POSIX since 2024, WCOREDUMP is the new default name.
WIFCORED is retained under _DEFAULT_SOURCE.

Fixes #19735.

Change-Id: Ic3f65e47b436bae92fe82ef73c3094be6bc9f29d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/9622
Reviewed-by: waddlesplash <[email protected]>
Tested-by: Commit checker robot <[email protected]>

headers/posix/sys/wait.h

@@ -6,6 +6,7 @@
 #define _SYS_WAIT_H
 
 
+#include <features.h>
 #include <sys/types.h>
 #include <signal.h>
 
@@ -25,9 +26,14 @@
 #define WTERMSIG(value)		(((value) >> 8) & 0xff)
 #define WIFSTOPPED(value)	((((value) >> 16) & 0xff) != 0)
 #define WSTOPSIG(value)		(((value) >> 16) & 0xff)
-#define WIFCORED(value)		((value) & 0x10000)
+#define WCOREDUMP(value)	((value) & 0x10000)
 #define WIFCONTINUED(value)	((value) & 0x20000)
 
+#ifdef _DEFAULT_SOURCE
+/* non-standard macro for backwards compatibility */
+#define WIFCORED(value)		WCOREDUMP(value)
+#endif
+
 /* ID types for waitid() */
 typedef enum {
 	P_ALL,		/* wait for any children, ignore ID */