OS: Archlinux x86_64
I've just compiled hhvm on `master` branch with GCC 4.9 released today.
It builds, but there are some warnings in the console output as seen below.
```
Scanning dependencies of t…
According to the RVC-CAL spec in section D.7.2.1:
> For list declaration, a more compact representation is available with an array style. `T myVar[N1][N2]..[Nn]` is equivalent to `List(type: List(ty…