Two small fixes

mysql-test/r/isam.result:
  Fixing results to match test changes
sql/sql_union.cc:
  Better fix for VC++

mysql-test/r/isam.result

 drop table if exists t1,t2;
 create table t1 (a tinyint not null auto_increment, b blob not null, primary key (a)) type=isam;
-Warnings:
-Warning	1263	Data truncated for column 'b' at row 1
-Warnings:
-Warning	1263	Data truncated for column 'b' at row 1
-Warnings:
-Warning	1263	Data truncated for column 'b' at row 1
-Warnings:
-Warning	1263	Data truncated for column 'b' at row 1
 delete from t1 where (a & 1);
 select sum(length(b)) from t1;
 sum(length(b))

sql/sql_union.cc

@@ -326,8 +326,8 @@ int st_select_lex_unit::exec()
 	  We get this from the difference of between total number of possible
 	  rows and actual rows added to the temporary table.
 	*/
-	add_rows+= (ulonglong) (thd->limit_found_rows - (table->file->records -
-							 records_at_start));
+	add_rows+= (ha_rows) (thd->limit_found_rows - (ulonglong)
+			      ((table->file->records -  records_at_start)));
       }
     }
   }