Keep additional copy of corner_cases.out due to the changed output format of PG v12

Author: ololobus

Diff for: expected/corner_cases_2.out

@@ -0,0 +1,64 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_pg_qs_1
+step s1_pg_qs_1: select pg_query_state(1);
+ERROR:  backend with pid=1 not found
+
+starting permutation: s1_pg_qs_2
+step s1_pg_qs_2: select pg_query_state(pg_backend_pid());
+ERROR:  attempt to extract state of current process
+
+starting permutation: s1_save_pid s2_pg_qs_counterpart
+step s1_save_pid: select save_own_pid(0);
+save_own_pid   
+
+               
+s2: INFO:  state of backend is idle
+step s2_pg_qs_counterpart: select pg_query_state(counterpart_pid(0));
+pg_query_state 
+
+
+starting permutation: s1_save_pid s1_disable_pg_qs s2_pg_qs_counterpart
+step s1_save_pid: select save_own_pid(0);
+save_own_pid   
+
+               
+step s1_disable_pg_qs: set pg_query_state.enable to off;
+s2: INFO:  query execution statistics disabled
+step s2_pg_qs_counterpart: select pg_query_state(counterpart_pid(0));
+pg_query_state 
+
+
+starting permutation: s1_set_bob s2_set_bob s1_save_pid s2_pg_qs_counterpart
+step s1_set_bob: set role bob;
+step s2_set_bob: set role bob;
+step s1_save_pid: select save_own_pid(0);
+save_own_pid   
+
+               
+s2: INFO:  state of backend is idle
+step s2_pg_qs_counterpart: select pg_query_state(counterpart_pid(0));
+pg_query_state 
+
+
+starting permutation: s1_set_bob s2_set_su s1_save_pid s2_pg_qs_counterpart
+step s1_set_bob: set role bob;
+step s2_set_su: set role super;
+step s1_save_pid: select save_own_pid(0);
+save_own_pid   
+
+               
+s2: INFO:  state of backend is idle
+step s2_pg_qs_counterpart: select pg_query_state(counterpart_pid(0));
+pg_query_state 
+
+
+starting permutation: s1_set_bob s2_set_alice s1_save_pid s2_pg_qs_counterpart
+step s1_set_bob: set role bob;
+step s2_set_alice: set role alice;
+step s1_save_pid: select save_own_pid(0);
+save_own_pid   
+
+               
+step s2_pg_qs_counterpart: select pg_query_state(counterpart_pid(0));
+ERROR:  permission denied