back-port from 5.1.

Bug#33812: mysql client incorrectly parsing DELIMITER
      
Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.

mysql-test/t/mysql_delimiter.sql

@@ -60,6 +60,12 @@ use test//
 show tables//
 delimiter ; # Reset delimiter
 
+#
+# Bug #33812: mysql client incorrectly parsing DELIMITER
+#
+select a as delimiter from t1
+delimiter ; # Reset delimiter
+
 #
 # Bug #36244: MySQL CLI doesn't recognize standalone -- as comment
 #             before DELIMITER statement