libmicrohttpd: fix clang compilation
libmicrohttpd: fix clang compilation

Backported upstream commits fixing compilation with llvm-dlltool.

Added the other clang targets as they work now.

Signed-off-by: Rosen Penev <cd9d359349c2d33dfd3bf458517d943871c7c054@gmail.com>

JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,lhmouse/MINGW-packages,fabiangreffrath/MINGW-packages,stahta01/MINGW-packages,Alexpux/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,fabiangreffrath/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,oroppas/MINGW-packages,oroppas/MINGW-packages,oroppas/MINGW-packages,Alexpux/MINGW-packages,stahta01/MINGW-packages,oroppas/MINGW-packages,JPeterMugaas/MINGW-packages,oroppas/MINGW-packages,oroppas/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,fabiangreffrath/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,oscarfv/MINGW-packages,fabiangreffrath/MINGW-packages,Alexpux/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,fabiangreffrath/MINGW-packages,stahta01/MINGW-packages,fabiangreffrath/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages