Bug#18736 test case 'upgrade' fails

"upgrade" failed on windows, because of lower_case_table_name.
This fix changes letters to lower case, not to depend on OS.

Note, this change does not affect coverage of 
Bug N 17142 "Crash if create with encoded name",
which the test war originally written for.

mysql-test/r/upgrade.result

@@ -41,19 +41,19 @@ t1
 t-1
 drop database `mysqltest1`;
 drop database `mysqltest-1`;
-drop table if exists `txu@0023P@0023p1`;
-drop table if exists `txu#P#p1`;
-create table `txu#P#p1` (s1 int);
-insert into `txu#P#p1` values (1);
-select * from `txu@0023P@0023p1`;
-ERROR 42S02: Table 'test.txu@0023P@0023p1' doesn't exist
-create table `txu@0023P@0023p1` (s1 int);
-insert into `txu@0023P@0023p1` values (2);
-select * from `txu@0023P@0023p1`;
+drop table if exists `txu@0023p@0023p1`;
+drop table if exists `txu#p#p1`;
+create table `txu#p#p1` (s1 int);
+insert into `txu#p#p1` values (1);
+select * from `txu@0023p@0023p1`;
+ERROR 42S02: Table 'test.txu@0023p@0023p1' doesn't exist
+create table `txu@0023p@0023p1` (s1 int);
+insert into `txu@0023p@0023p1` values (2);
+select * from `txu@0023p@0023p1`;
 s1
 2
-select * from `txu#P#p1`;
+select * from `txu#p#p1`;
 s1
 1
-drop table `txu@0023P@0023p1`;
-drop table `txu#P#p1`;
+drop table `txu@0023p@0023p1`;
+drop table `txu#p#p1`;

mysql-test/t/upgrade.test

@@ -34,16 +34,16 @@ drop database `mysqltest-1`;
 # Bug#17142: Crash if create with encoded name
 #
 --disable_warnings
-drop table if exists `txu@0023P@0023p1`;
-drop table if exists `txu#P#p1`;
+drop table if exists `txu@0023p@0023p1`;
+drop table if exists `txu#p#p1`;
 --enable_warnings
-create table `txu#P#p1` (s1 int);
-insert into `txu#P#p1` values (1);
+create table `txu#p#p1` (s1 int);
+insert into `txu#p#p1` values (1);
 --error 1146
-select * from `txu@0023P@0023p1`;
-create table `txu@0023P@0023p1` (s1 int);
-insert into `txu@0023P@0023p1` values (2);
-select * from `txu@0023P@0023p1`;
-select * from `txu#P#p1`;
-drop table `txu@0023P@0023p1`;
-drop table `txu#P#p1`;
+select * from `txu@0023p@0023p1`;
+create table `txu@0023p@0023p1` (s1 int);
+insert into `txu@0023p@0023p1` values (2);
+select * from `txu@0023p@0023p1`;
+select * from `txu#p#p1`;
+drop table `txu@0023p@0023p1`;
+drop table `txu#p#p1`;