Bug#52062: Compiler warning in os0file.c on windows 64-bit On Windows, the parameter for number of bytes passed into WriteFile() and ReadFile() is DWORD. Casting is needed to silence the warning on 64-bit Windows.
Bug#52062: Compiler warning in os0file.c on windows 64-bit
On Windows, the parameter for number of bytes passed into WriteFile()
and ReadFile() is DWORD. Casting is needed to silence the warning on
64-bit Windows.

Also, adding several asserts to ensure the variable for number of bytes
is no more than 32 bits, even on 64-bit Windows.

rb://415
Approved by: Inaam

slanterns/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,ollie314/server,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix