does not use the GC memory in json

ext/json/fbuffer/fbuffer.h

@@ -5,6 +5,20 @@
 #include <assert.h>
 #include "ruby.h"
 
+#ifdef __MACRUBY__
+/* We cannot use the GC memory functions here
+ * function will call free() on the memory, resulting in a leak.
+ */
+# undef ALLOC
+# define ALLOC(type) (type*)malloc(sizeof(type))
+# undef ALLOC_N
+# define ALLOC_N(type,n) ((type *)malloc(sizeof(type) * (n)))
+# undef REALLOC_N
+# define REALLOC_N(var,type,n) \
+    (var)=(type*)realloc((char*)(var),(n) * sizeof(type))
+# define ruby_xfree(x) free(x)
+#endif
+
 #ifdef HAVE_RUBY_ENCODING_H
 #include "ruby/encoding.h"
 #define FORCE_UTF8(obj) rb_enc_associate((obj), rb_utf8_encoding())