v8js: V8 crashing on toLocaleString()

The following expression crashes V8JS:

var date = new Date("10/11/2009"),
    locale = "en-us",
    month = date.toLocaleString(locale, { month: "long" });

Results in:

 kernel: [10936.602251] traps: php-fpm[8516] trap invalid opcode ip:7f9239f2526f sp:7ffff8f825f8 error:0 in libv8_libbase.so[7f9239f16000+14000]

The problem is toLocaleString() call.

I realize it’s not the fault of V8JS… But maybe @stesie has an idea of what’s happening? It was fine with 5.5.x versions of V8.

Thanks!