[8u40] review request: RT-39182: Enable building 32-bit Linux on 64-bit systems

[Kevin Rushforth]

Dave, Kirill, Anton, Chris,

Please review the following build changes to enable building 32-bit 
graphics, media, webkit, and packager binaries on a 64-bit Linux system.

https://javafx-jira.kenai.com/browse/RT-39182
http://cr.openjdk.java.net/~kcr/RT-39182/webrev.01/

Details are in JIRA.

-- Kevin