Changed mysql-test to print warnings for not existing table to DROP TABLE

Cleaned up test; Removed wrong DROP TABLE commands and use standard table and database names.
changed store_warning() -> push_warning_print()

mysql-test/t/func_regexp.test

@@ -2,7 +2,10 @@
 # Some regexp tests
 #
 
+--disable_warnings
 drop table if exists t1;
+--enable_warnings
+
 create table t1 (s1 char(64),s2 char(64));
 
 insert into t1 values('aaa','aaa');