module:re: Modified the subn to use the callable builtin
module:re: Modified the subn to use the callable builtin

Previous implementation did not have access to the `callable` builtin
because it had not been implemented yet. This commit updates the subn
method to use callable so that an exception in the user's passed
method can propagate correctly.

QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt