Version 3.25.4 (based on bleeding_edge revision r19679)

x64: Fix LMathMinMax for constant Smi right-hand operands (Chromium issue 349079).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@19680 ce2b1a6d-e550-0410-aec6-3dcde31c8c00