void fill(Context other) {
            searchChainRegistry = other.searchChainRegistry;
            indexFacts = other.indexFacts;
            schemaInfo = other.schemaInfo;
            tokenRegistry = other.tokenRegistry;
            rendererRegistry = other.rendererRegistry;
            detailedDiagnostics = other.detailedDiagnostics;
            breakdown = other.breakdown;
            linguistics = other.linguistics;
            executor = other.executor;
        }
The brutal version of populateFrom().

@param other a Context instance this will copy all state from
container-search/src/main/java/com/yahoo/search/searchchain/Execution.java