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/fmtmsg.h

@@ -0,0 +1,42 @@
+#ifndef _FMTMSG_H
+#define _FMTMSG_H 1
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fmtmsg.h.html
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define MM_HARD		1
+#define MM_SOFT		2
+#define MM_FIRM		3
+#define MM_APPL		4
+#define MM_UTIL		5
+#define MM_OPSYS	6
+#define MM_RECOVER	7
+#define MM_NRECOV	8
+#define MM_HALT		9
+#define MM_ERROR	10
+#define MM_WARNING	11
+#define MM_INFO		12
+#define MM_NOSEV	13
+#define MM_PRINT	14
+#define MM_CONSOLE	15
+
+#define MM_NULLLBL	(char*)0
+#define MM_NULLSEV	0
+#define MM_NULLMC	0L
+#define MM_NULLTXT	(char*)0
+#define MM_NULLACL	(char*)0
+#define MM_NULLTAG	(char*)0
+
+#define MM_OK		0
+#define MM_NOTOK	1
+#define MM_NOMSG	2
+#define MM_NOCON	3
+
+int fmtmsg(long classification, const char* label, int severity, const char* text, const char* action, const char* tag);
+
+__END_DECLS
+
+#endif