Fix pcntl Haiku build

guarding SIGIO constant.

Closes GH-8612.

Author: devnexen

NEWS

@@ -21,6 +21,9 @@ PHP                                                                        NEWS
   . Fixed bug GH-8466 (ini_get() is optimized out when the option does not
     exist). (Arnaud)
 
+- Pcntl:
+  . Fixed Haiku build. (David Carlier)
+
 - Soap:
   . Fixed bug GH-8578 (Error on wrong parameter on SoapHeader constructor).
     (robertnisipeanu)

ext/pcntl/pcntl.c

@@ -151,7 +151,9 @@ void php_register_signal_constants(INIT_FUNC_ARGS)
 #ifdef SIGPOLL
 	REGISTER_LONG_CONSTANT("SIGPOLL",  (zend_long) SIGPOLL, CONST_CS | CONST_PERSISTENT);
 #endif
+#ifdef SIGIO
 	REGISTER_LONG_CONSTANT("SIGIO",    (zend_long) SIGIO, CONST_CS | CONST_PERSISTENT);
+#endif
 #ifdef SIGPWR
 	REGISTER_LONG_CONSTANT("SIGPWR",   (zend_long) SIGPWR, CONST_CS | CONST_PERSISTENT);
 #endif