这里有个x64 PGO nightly编译版for windows

有兴趣的可以使用 我感觉不错 适合玩家 每天都会更新（自动化编译）
http://fbuild.com/

mozilla-central builds almost every day.
The compiler is Visual Studio 2010 (VC + +10) is used.
Windows SDK, SDK DirectX is using the latest version.
Compile option to focus on execution speed. Size much bigger binary do not care.
to build a version of x64 native binaries.
x64 patch version for building essential.
Be spent on appropriate patches like that.
Unless such failure is not fatal start to expose even without noticeable defects.