mruby-bigint: add conditional mruby/hash.h include for debug functions

Added #ifdef MRB_DEBUG conditional include for mruby/hash.h to support
debug functions that use hash operations. This enables pool statistics
and debugging functionality when MRB_DEBUG is defined without affecting
production builds.

Co-authored-by: Claude <noreply@anthropic.com>
EOF < /dev/null

mrbgems/mruby-bigint/core/bigint.c

@@ -10,6 +10,9 @@
 #include <mruby/array.h>
 #include <mruby/string.h>
 #include <mruby/internal.h>
+#ifdef MRB_DEBUG
+#include <mruby/hash.h>
+#endif
 #include <string.h>
 #include "bigint.h"