misdetects 32bit userland as 64bit with a 64bit kernel

I'm running a 64bit Kernel with a 32bit Userland here and configure misdetects this as a 64bit system. This results in the compiler not finding its own system headers because there's no 64bit versions of them installed.

Since this is a pure 32bit userland, configure should detect that and pass -m32 to the compiler when building qmake instead of the -m64 it uses right now.