* Remove old patch to link again `-lamstrmid`; that is already fixed in Qt itself
* Add new patch to avoid linker errors via `-Wl,--allow-multiple-definition`
* The conflicting symbols are likely supposed to be defined via `__declspec(selectany)`
which somehow doesn't work
* Only packages for additional modules are covered so far
* Only packages for mingw-w64 target are covered so far
* This leads to small adjustments/unifications within the
PKGBUILDs; not tested yet
* Adapt hacks to new config system
* Use distinct mkspec mingw-w64-g++ rather than
patching the existing win32-g++
* Testing QML and ANGLE is on TODO list
because it hasn't been tested since quite a time