common: implement s_get_row and s_get_name in ivy_file

common/include/ivy/file.h

@@ -5,12 +5,16 @@
 #include <ivy/misc.h>
 #include <stdio.h>
 
+struct b_array;
+
 struct ivy_file {
 	struct ivy_line_source f_base;
+	struct b_array *f_lines;
+	char *f_path;
 	FILE *f_fp;
 };
 
-IVY_API struct ivy_file *ivy_file_from_fp(FILE *fp);
+IVY_API enum ivy_status ivy_file_open(const char *path, struct ivy_file **out);
 IVY_API void ivy_file_close(struct ivy_file *file);
 
 #endif