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/utmpx.h

@@ -0,0 +1,43 @@
+#ifndef _UTMPX_H
+#define _UTMPX_H 1
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/utmpx.h.html
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define __need_pid_t
+#include <sys/types.h>
+
+#include <sys/time.h>
+
+struct utmpx
+{
+	char			ut_user[32];	/* User login name. */
+	char			ut_id[4];		/* Unspecified initialization process identifier. */
+	char			ut_line[32];	/* Device name. */
+	pid_t			ut_pid;			/* Process ID. */
+	short			ut_type;		/* Type of entry. */
+	struct timeval	ut_tv;			/* Time entry was made. */
+};
+
+#define EMPTY			0
+#define BOOT_TIME		1
+#define OLD_TIME		2
+#define NEW_TIME		3
+#define USER_PROCESS	4
+#define INIT_PROCESS	5
+#define LOGIN_PROCESS	6
+#define DEAD_PROCESS	7
+
+void			endutxent(void);
+struct utmpx*	getutxent(void);
+struct utmpx*	getutxid(const struct utmpx* id);
+struct utmpx*	getutxline(const struct utmpx* line);
+struct utmpx*	pututxline(const struct utmpx* utmpx);
+void			setutxent(void);
+
+__END_DECLS
+
+#endif