[Development] Qt 5.10 pre-built bunaries

[Jani Heikkinen]

Hi,

As a conclusion of subject:

only change related to pre-built binaries for 5.10 (from Qt 5.9) is dropping 32 bit iOS.
And from 5.11 -> we will drop MSVC2013 as well.

There isn't conclusion about mingw yet but let's agree to switch from mingw 32 bit to 64 bit one in 5.11 -> 

There were also discussion about minimum GCC version but it isn't directly related to pre-built binaries and that's why it needs to be concluded in different thread

br
Jani