Remove abstime, reltime, tinterval tables from old regression databases.

In the back branches, drop these tables after the regression tests are
done with them.  This fixes failures of cross-branch pg_upgrade testing
caused by these types having been removed in v12.  We do lose the ability
to test dump/restore behavior with these types in the back branches, but
the actual loss of code coverage seems to be nil given that there's nothing
very special about these types.

Discussion: https://postgr.es/m/20181009192237.34wjp3nmw7oynmmr@alap3.anarazel.de

src/test/regress/expected/horology.out

@@ -2965,3 +2965,10 @@ SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD HH:MI:SS TZ');
 (1 row)
 
 RESET TIME ZONE;
+--
+-- Drop tables that we don't want to keep because they interfere with
+-- testing pg_upgrade to v12 and up
+--
+DROP TABLE abstime_tbl;
+DROP TABLE reltime_tbl;
+DROP TABLE tinterval_tbl;

src/test/regress/expected/sanity_check.out

@@ -13,7 +13,6 @@ SELECT relname, relhasindex
 -------------------------+-------------
  a                       | f
  a_star                  | f
- abstime_tbl             | f
  aggtest                 | f
  array_index_op_test     | t
  array_op_test           | f
@@ -142,7 +141,6 @@ SELECT relname, relhasindex
  radix_text_tbl          | t
  ramp                    | f
  real_city               | f
- reltime_tbl             | f
  road                    | t
  shighway                | t
  slow_emp4000            | f
@@ -166,9 +164,8 @@ SELECT relname, relhasindex
  timestamp_tbl           | f
  timestamptz_tbl         | f
  timetz_tbl              | f
- tinterval_tbl           | f
  varchar_tbl             | f
-(157 rows)
+(154 rows)
 
 --
 -- another sanity check: every system catalog that has OIDs should have

src/test/regress/sql/horology.sql

@@ -477,3 +477,12 @@ SELECT '2012-12-12 12:00 America/New_York'::timestamptz;
 SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD HH:MI:SS TZ');
 
 RESET TIME ZONE;
+
+--
+-- Drop tables that we don't want to keep because they interfere with
+-- testing pg_upgrade to v12 and up
+--
+
+DROP TABLE abstime_tbl;
+DROP TABLE reltime_tbl;
+DROP TABLE tinterval_tbl;