remove unused method.h from kernel.c

src/kernel.c

@@ -19,7 +19,20 @@
 #include "mruby/variable.h"
 #include "mruby/khash.h"
 #include "error.h"
-#include "method.h"
+
+typedef enum {
+    NOEX_PUBLIC    = 0x00,
+    NOEX_NOSUPER   = 0x01,
+    NOEX_PRIVATE   = 0x02,
+    NOEX_PROTECTED = 0x04,
+    NOEX_MASK      = 0x06,
+    NOEX_BASIC     = 0x08,
+    NOEX_UNDEF     = NOEX_NOSUPER,
+    NOEX_MODFUNC   = 0x12,
+    NOEX_SUPER     = 0x20,
+    NOEX_VCALL     = 0x40,
+    NOEX_RESPONDS  = 0x80
+} mrb_method_flag_t;
 
 #ifdef INCLUDE_REGEXP
 #include "re.h"