bug-1592608 BLOB/TEXT/BINARY Checksum uses CRC32

t/pt-table-checksum/samples/issue_1592608.sql

@@ -0,0 +1,11 @@
+CREATE SCHEMA IF NOT EXISTS bug_1592608;
+USE bug_1592608;
+DROP TABLE IF EXISTS t;
+CREATE TABLE t (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, 
+  a  MEDIUMTEXT, 
+  b  MEDIUMBLOB
+)engine=innodb;
+
+INSERT INTO t (a, b) VALUES (REPEAT('a', 2097152*2), CAST(REPEAT('a', 2097152*2) AS BINARY));
+