[BACKPORT 2.6][YSQL] [#9572] Correctly determine is_yb_relation for row-marked relations when preparing target list

Summary:
Presently, when iterating through the row-marked relations to add the necessary columns to the target list, we determined whether to get the YB TID or the CTID based on the target relation. However, this check should be done using the row-marked relation instead.
The previous version of the code fails to work when the target relation is a YB relation and the row-marked relation is a temporary relation.
(Eg: `UPDATE test1 SET z = 2 FROM test2 WHERE test1.x = test2.x;` where test2 is a temporary relation and test1 is a YB relation)

Original Commit: [[ f148418 | f148418 ]]

Original Differential Revision: https://phabricator.dev.yugabyte.com/D12994

Test Plan:
Jenkins: rebase: 2.6

Run `TestPgRegressFeature` to execute `yb_feature_temp`

Reviewers: mihnea, amartsinchyk

Reviewed By: amartsinchyk

Differential Revision: https://phabricator.dev.yugabyte.com/D13108

Author: Fizaa Luthra

src/postgres/src/backend/optimizer/prep/preptlist.c

@@ -143,13 +143,7 @@ preprocess_targetlist(PlannerInfo *root)
 
 		if (rc->allMarkTypes & ~(1 << ROW_MARK_COPY))
 		{
-			bool is_yb_relation = false;
-			if (!target_relation)
-				is_yb_relation = IsYBRelationById(getrelid(rc->rti, range_table));
-			else
-				is_yb_relation = IsYBBackedRelation(target_relation);
-
-			if (is_yb_relation)
+			if (IsYBRelationById(getrelid(rc->rti, range_table)))
 			{
 				/* Need to fetch YB TID */
 				var = makeVar(rc->rti,

src/postgres/src/test/regress/expected/yb_feature_temp.out

@@ -367,3 +367,13 @@ INSERT INTO temptest VALUES (101, 201, 301), (101, 201, 301);
 ERROR:  duplicate key value violates unique constraint "temptest_pkey"
 DETAIL:  Key (k)=(101) already exists.
 DROP TABLE temptest;
+-- test temp table being used to update YB table.
+CREATE TABLE test1 (x int, y int, z int);
+INSERT INTO test1 VALUES (1, 2, 3);
+CREATE TEMP TABLE test2 as table test1;
+UPDATE test1 SET z = 2 FROM test2 WHERE test1.x = test2.x;
+SELECT * FROM test1;
+ x | y | z
+---+---+---
+ 1 | 2 | 2
+(1 row)

src/postgres/src/test/regress/sql/yb_feature_temp.sql

@@ -303,3 +303,10 @@ INSERT INTO temptest VALUES (100, 200, 300);
 INSERT INTO temptest VALUES (101, 201, 301), (101, 201, 301);
 
 DROP TABLE temptest;
+
+-- test temp table being used to update YB table.
+CREATE TABLE test1 (x int, y int, z int);
+INSERT INTO test1 VALUES (1, 2, 3);
+CREATE TEMP TABLE test2 as table test1;
+UPDATE test1 SET z = 2 FROM test2 WHERE test1.x = test2.x;
+SELECT * FROM test1;