[Releasing] Updating the mingw version for 5.4 (CI/packaging)

[Harri Porten]

Hello Kai,

On Thu, 18 Sep 2014, Koehne Kai wrote:

> I'd like to suggest updating the MinGW version we build binaries for 
> once more for Qt 5.4. The suggested toolchain would be mingw-builds 
> i686-4.9.1-release-posix-dwarf-rt_v3-rev1 [1].

Could you explain how this would affect ABI compatibility? I.e. can 
binaries compiled with the new compiler link against libraries build 
with i686-4.8.2-release-posix-dwarf-rt_v3-rev3?

I see that at least the threading and exception models are the same. Which 
would be nice.

Harri.