ASTERIXDB-1005, ASTERIXDB-1263: Clean up subplan flattening:
1. Inline NestedTupleSource and remove SubplanOperator for special cases that
   join operators inside the SubplanOperator can be re-targeted for
   correlations;
2. Blindly inline NestedTupleSource and remove SubplanOperator for general cases
   where the condition of the special case is not met.

Change-Id: I4dd130a25f3c81272cc23f844ea20e376e990612
Reviewed-on: https://asterix-gerrit.ics.uci.edu/579
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
diff --git a/asterix-app/src/test/resources/optimizerts/queries/nested_loj2.aql b/asterix-app/src/test/resources/optimizerts/queries/nested_loj2.aql
index 43c2722..f7504ad 100644
--- a/asterix-app/src/test/resources/optimizerts/queries/nested_loj2.aql
+++ b/asterix-app/src/test/resources/optimizerts/queries/nested_loj2.aql
@@ -88,4 +88,4 @@
 return {
   "cust": $c,
   "orders": $orders
-}  
+}