Add sigprocmask(2) stub.

libc/Makefile

@@ -312,6 +312,7 @@ SIG_DFL.o \
 SIG_ERR.o \
 SIG_IGN.o \
 signal.o \
+sigprocmask.o \
 sleep.o \
 stat.o \
 stdio.o \

libc/sigprocmask.cpp

@@ -0,0 +1,34 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    sigprocmask.cpp
+    Examine and change blocked signals.
+
+*******************************************************************************/
+
+#include <signal.h>
+#include <stdio.h>
+
+extern "C" int sigprocmask(int how, const sigset_t* set, sigset_t* oldset)
+{
+	(void) how;
+	(void) set;
+	(void) oldset;
+	return 0;
+}