BuildSystem: Move all userpace libraries under the userspace directory

As the number of libraries is increasing, root directory starts to
expand. This adds better organization for libraries

userspace/libraries/LibC/include/sys/resource.h

@@ -0,0 +1,56 @@
+#ifndef _SYS_RESOURCE_H
+#define _SYS_RESOURCE_H 1
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_resource.h.html
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define __need_id_t
+#include <sys/types.h>
+
+#include <sys/time.h>
+
+#define PRIO_PROCESS	0
+#define PRIO_PGRP		1
+#define PRIO_USER		2
+
+typedef unsigned int rlim_t;
+
+#define RLIM_INFINITY	((rlim_t)-1)
+#define RLIM_SAVED_MAX	RLIM_INFINITY
+#define RLIM_SAVED_CUR	RLIM_INFINITY
+
+#define RUSAGE_SELF		0
+#define RUSAGE_CHILDREN 1
+
+struct rlimit
+{
+	rlim_t rlim_cur;	/* The current (soft) limit. */
+	rlim_t rlim_max;	/* The hard limit. */
+};
+
+struct rusage
+{
+	struct timeval ru_utime;	/* User time used. */
+	struct timeval ru_stime;	/* System time used. */
+};
+
+#define RLIMIT_CORE		0
+#define RLIMIT_CPU		1
+#define RLIMIT_DATA		2
+#define RLIMIT_FSIZE	3
+#define RLIMIT_NOFILE	4
+#define RLIMIT_STACK	5
+#define RLIMIT_AS		6
+
+int getpriority(int which, id_t who);
+int getrlimit(int resource, struct rlimit* rlp);
+int getrusage(int who, struct rusage* r_usage);
+int setpriority(int which, id_t who, int value);
+int setrlimit(int resource, const struct rlimit* rlp);
+
+__END_DECLS
+
+#endif