[Win] Improve support for command line builds of 64-bit JSC
https://bugs.webkit.org/show_bug.cgi?id=124380

Patch by Brent Fulgham <bfulgham@apple.com> on 2013-11-14
Reviewed by David Kilzer.

* Scripts/webkitdirs.pm:
(argumentsForConfiguration): Recognize all flavors of Debug and Release (i.e., 'Debug',
'Debug|Win32', 'Debug|x64') when passing arguments to child processes.
(determinePassedConfiguration): Don't suffix configuration with "|Win32" or "|x64". That's
what the "$configurationForVisualStudio" value is for.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159328 268f45cc-cd09-0410-ab3c-d52691b4dbfc