'Return a constant pointer for the environment object.'

def as_pointer(self, targetctx, ptrty=types.pyobject):

    ll_addr = targetctx.get_value_type(types.intp)
    ll_ptr = targetctx.get_value_type(ptrty)
    envptr = ll_addr(id(self)).inttoptr(ll_ptr)
    return envptr
