mruby-builder: Add -g when mruby is built with debug
This keeps the debug information, allowing backtraces to function.
@@ -70,6 +70,7 @@ assert attrs ? gems == false;
(set -x
rm -f irep.{c,o}
mrbc \
+ ${optionalString mruby.debug "-g"} \
-Bruby_irep \
-oirep.c \
"$@"
