Cosmetic improvement for psql opfamily-related information

 * Rename column "Opfamily Name" to "Operator family" for uniformity.
 * Rename column alias from "t1" to "t".

src/bin/psql/describe.c

@@ -6102,7 +6102,7 @@ listOperatorClasses(const char *access_method_pattern,
 					  "\nFROM pg_catalog.pg_opclass c\n"
 					  "  LEFT JOIN pg_catalog.pg_am am on am.oid = c.opcmethod\n"
 					  "  LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.opcnamespace\n"
-					  "  LEFT JOIN pg_catalog.pg_type t1 ON t1.oid = c.opcintype\n"
+					  "  LEFT JOIN pg_catalog.pg_type t ON t.oid = c.opcintype\n"
 		);
 	if (verbose)
 		appendPQExpBuffer(&buf,
@@ -6114,7 +6114,7 @@ listOperatorClasses(const char *access_method_pattern,
 										   false, false, NULL, "am.amname", NULL, NULL);
 	if (type_pattern)
 		processSQLNamePattern(pset.db, &buf, type_pattern, have_where, false,
-							  NULL, "t1.typname", NULL, NULL);
+							  NULL, "t.typname", NULL, NULL);
 
 	appendPQExpBufferStr(&buf, "ORDER BY 1, 2, 4;");
 	res = PSQLexec(buf.data);
@@ -6250,7 +6250,7 @@ listOpFamilyOperators(const char *access_method_pattern,
 					  "    pg_catalog.format_type(o.amoprighttype, NULL)\n"
 					  "  ) AS \"%s\"\n",
 					  gettext_noop("AM"),
-					  gettext_noop("Opfamily Name"),
+					  gettext_noop("Operator family"),
 					  gettext_noop("Operator"));
 
 	if (verbose)

src/test/regress/expected/psql.out

@@ -4954,8 +4954,8 @@ List of access methods
 
 \dAo+ btree float_ops
                                  List of operators of operator families
-  AM   | Opfamily Name |                Operator                 | Strategy | Purpose | Sort opfamily 
--------+---------------+-----------------------------------------+----------+---------+---------------
+  AM   | Operator family |                Operator                 | Strategy | Purpose | Sort opfamily 
+-------+-----------------+-----------------------------------------+----------+---------+---------------
  btree | float_ops       | < (double precision, double precision)  |        1 | search  | 
  btree | float_ops       | <= (double precision, double precision) |        2 | search  | 
  btree | float_ops       | = (double precision, double precision)  |        3 | search  | 
@@ -4980,8 +4980,8 @@ List of access methods
 
 \dAo * pg_catalog.jsonb_path_ops
     List of operators of operator families
- AM  | Opfamily Name  |       Operator       
------+----------------+----------------------
+ AM  | Operator family |       Operator       
+-----+-----------------+----------------------
  gin | jsonb_path_ops  | @> (jsonb, jsonb)
  gin | jsonb_path_ops  | @? (jsonb, jsonpath)
  gin | jsonb_path_ops  | @@ (jsonb, jsonpath)