Disable __xpg_sigpause until it is implemented (if at all) in uClibc

include/signal.h

@@ -159,7 +159,7 @@ extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 # define sigpause(mask) __sigpause ((mask), 0)
 #else
 # ifdef __USE_XOPEN
-#  ifdef __GNUC__
+#  if 0 /* def __GNUC__ */
 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 #  else
 /* Remove a signal from the signal mask and suspend the process.  */