Remove unused structures.

src/class.c

@@ -18,14 +18,6 @@
 
 KHASH_DEFINE(mt, mrb_sym, struct RProc*, 1, kh_int_hash_func, kh_int_hash_equal)
 
-typedef struct fc_result {
-    mrb_sym name;
-    struct RClass * klass;
-    mrb_value path;
-    struct RClass * track;
-    struct fc_result *prev;
-} fcresult_t;
-
 void
 mrb_gc_mark_mt(mrb_state *mrb, struct RClass *c)
 {

src/error.h

@@ -7,10 +7,6 @@
 #ifndef MRUBY_ERROR_H
 #define MRUBY_ERROR_H
 
-struct RException {
-  MRB_OBJECT_HEADER;
-};
-
 void mrb_sys_fail(mrb_state *mrb, const char *mesg);
 void mrb_bug_errno(const char*, int);
 int sysexit_status(mrb_state *mrb, mrb_value err);

src/hash.c

@@ -526,11 +526,6 @@ mrb_hash_delete(mrb_state *mrb, mrb_value self)
   mrb_get_args(mrb, "o", &key);
   return mrb_hash_delete_key(mrb, self, key);
 }
-struct shift_var {
-    mrb_value key;
-    mrb_value val;
-};
-
 
 /* 15.2.13.4.24 */
 /*

src/kernel.c

@@ -26,12 +26,6 @@ typedef enum {
     NOEX_RESPONDS  = 0x80
 } mrb_method_flag_t;
 
-struct obj_ivar_tag {
-  mrb_value obj;
-  int (*func)(mrb_sym key, mrb_value val, void * arg);
-  void * arg;
-};
-
 int
 mrb_obj_basic_to_s_p(mrb_state *mrb, mrb_value obj)
 {