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/renameat.c b/renameat.c
new file mode 100644
index 0000000..bf3dd79
--- /dev/null
+++ b/renameat.c
@@ -0,0 +1,33 @@
+#include "defs.h"
+
+static void
+decode_renameat(struct tcb *tcp)
+{
+	print_dirfd(tcp, tcp->u_arg[0]);
+	printpath(tcp, tcp->u_arg[1]);
+	tprints(", ");
+	print_dirfd(tcp, tcp->u_arg[2]);
+	printpath(tcp, tcp->u_arg[3]);
+}
+
+int
+sys_renameat(struct tcb *tcp)
+{
+	if (entering(tcp)) {
+		decode_renameat(tcp);
+	}
+	return 0;
+}
+
+#include "xlat/rename_flags.h"
+
+int
+sys_renameat2(struct tcb *tcp)
+{
+	if (entering(tcp)) {
+		decode_renameat(tcp);
+		tprints(", ");
+		printflags(rename_flags, tcp->u_arg[4], "RENAME_??");
+	}
+	return 0;
+}