Move libgen.h functions into their own directory.

libc/Makefile

@@ -168,7 +168,6 @@ arpa/inet/inet_addr.o \
 arpa/inet/inet_ntoa.o \
 arpa/inet/inet_ntop.o \
 arpa/inet/inet_pton.o \
-basename.o \
 calltrace.o \
 canonicalize_file_name_at.o \
 canonicalize_file_name.o \
@@ -186,7 +185,6 @@ $(CPUDIR)/syscall.o \
 creat.o \
 dirent/fddir-sortix.o \
 dirent/scandir.o \
-dirname.o \
 dispmsg_issue.o \
 dlfcn.o \
 dup2.o \
@@ -257,6 +255,8 @@ isatty.o \
 kernelinfo.o \
 kill.o \
 lchown.o \
+libgen/basename.o \
+libgen/dirname.o \
 linkat.o \
 link.o \
 localeconv.o \

libc/libgen/basename.cpp

@@ -17,7 +17,7 @@
     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/>.
 
-    basename.cpp
+    libgen/basename.cpp
     Returns the name part of a path.
 
 *******************************************************************************/

libc/libgen/dirname.cpp

@@ -17,7 +17,7 @@
     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/>.
 
-    dirname.cpp
+    libgen/dirname.cpp
     Returns the directory part of a path.
 
 *******************************************************************************/