Create 'main' test directory and move 't' and 'r' there

mysql-test/main/bulk_replace.test

@@ -0,0 +1,15 @@
+#
+# this is a test of bulk-insert code
+#
+
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+CREATE TABLE t1 (a int, unique (a), b int not null, unique(b), c int not null, index(c));
+replace into t1 values (1,1,1),(2,2,2),(3,1,3);
+--sorted_result
+select * from t1;
+check table t1;
+drop table t1;
+
+# End of 4.1 tests