Merge large_object.sql test into largeobject.source.

It seems pretty confusing to have tests named both largeobject and
large_object.  The latter is of very recent vintage (commit ff992c074),
so get rid of it in favor of merging into the former.

Also, enable the LO comment test that was added by commit 70ad7ed4e,
since the later commit added the then-missing pg_upgrade functionality.
The large_object.sql test case is almost completely redundant with that,
but not quite: it seems like creating a user-defined LO with an OID in
the system range might be an interesting case for pg_upgrade, so let's
keep it.

Like the earlier patch, back-patch to all supported branches.

Discussion: https://postgr.es/m/18665.1500306372@sss.pgh.pa.us

src/test/regress/expected/large_object.out

@@ -1,15 +0,0 @@
--- This is more-or-less DROP IF EXISTS LARGE OBJECT 3001;
-WITH unlink AS (SELECT lo_unlink(loid) FROM pg_largeobject WHERE loid = 3001) SELECT 1;
- ?column? 
-----------
-        1
-(1 row)
-
--- Test creation of a large object and leave it for testing pg_upgrade
-SELECT lo_create(3001);
- lo_create 
------------
-      3001
-(1 row)
-
-COMMENT ON LARGE OBJECT 3001 IS 'testing comments';

src/test/regress/input/largeobject.source

@@ -170,4 +170,11 @@ SELECT pageno, data FROM pg_largeobject WHERE loid = :newloid;
 SELECT lo_unlink(loid) FROM lotest_stash_values;
 \lo_unlink :newloid
 
-TRUNCATE lotest_stash_values;
+-- Create one more object that we leave behind for testing pg_dump/pg_upgrade;
+-- this one intentionally has an OID in the system range
+SELECT lo_create(3001);
+
+COMMENT ON LARGE OBJECT 3001 IS 'testing comments';
+
+-- Clean up
+DROP TABLE lotest_stash_values;

src/test/regress/output/largeobject.source

@@ -291,4 +291,14 @@ SELECT lo_unlink(loid) FROM lotest_stash_values;
 (1 row)
 
 \lo_unlink :newloid
-TRUNCATE lotest_stash_values;
+-- Create one more object that we leave behind for testing pg_dump/pg_upgrade;
+-- this one intentionally has an OID in the system range
+SELECT lo_create(3001);
+ lo_create 
+-----------
+      3001
+(1 row)
+
+COMMENT ON LARGE OBJECT 3001 IS 'testing comments';
+-- Clean up
+DROP TABLE lotest_stash_values;

src/test/regress/output/largeobject_1.source

@@ -291,4 +291,14 @@ SELECT lo_unlink(loid) FROM lotest_stash_values;
 (1 row)
 
 \lo_unlink :newloid
-TRUNCATE lotest_stash_values;
+-- Create one more object that we leave behind for testing pg_dump/pg_upgrade;
+-- this one intentionally has an OID in the system range
+SELECT lo_create(3001);
+ lo_create 
+-----------
+      3001
+(1 row)
+
+COMMENT ON LARGE OBJECT 3001 IS 'testing comments';
+-- Clean up
+DROP TABLE lotest_stash_values;

src/test/regress/parallel_schedule

@@ -83,7 +83,7 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 # Another group of parallel tests
 # ----------
-test: privileges security_label collate large_object
+test: privileges security_label collate
 
 test: misc
 # rules cannot run concurrently with any test that creates a view

src/test/regress/serial_schedule

@@ -94,7 +94,6 @@ test: prepared_xacts
 test: privileges
 test: security_label
 test: collate
-test: large_object
 test: misc
 test: rules
 test: select_views

src/test/regress/sql/large_object.sql

@@ -1,7 +0,0 @@
--- This is more-or-less DROP IF EXISTS LARGE OBJECT 3001;
-WITH unlink AS (SELECT lo_unlink(loid) FROM pg_largeobject WHERE loid = 3001) SELECT 1;
-
--- Test creation of a large object and leave it for testing pg_upgrade
-SELECT lo_create(3001);
-
-COMMENT ON LARGE OBJECT 3001 IS 'testing comments';