file.c: move renameat and renameat2 parsers to a separate file

* renameat.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* file.c: Move sys_renameat, sys_renameat2, and related code
to renameat.c.
diff --git a/Makefile.am b/Makefile.am
index e4b7852..324be2b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -54,6 +54,7 @@
 	ptp.c		\
 	quota.c		\
 	reboot.c	\
+	renameat.c	\
 	resource.c	\
 	scsi.c		\
 	signal.c	\