Properly set location on converted constants
Properly set location on converted constants

OPA converts lone bodies to rules containing a single expression
in their bodies (true). However, the parser extension that did this
neglected to set the location of the new rule and the new expression.

open-policy-agent/opa,tsandall/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,open-policy-agent/opa,Eva-xiaohui-luo/opa,Eva-xiaohui-luo/opa,tsandall/opa,tsandall/opa,Eva-xiaohui-luo/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa