Compiling python with "-Wl,-stack_size,1000000" causes problems when
compiling for example pygobject3. pygobject3 uses "python3.x-config
--ldflags" during installation and then fails when
"-Wl,-stack_size,1000000" is present. Maybe we should investigate
removing this during the build of pyobject3, but this stack_size flag is
also not used on the popular darwin homebrew-core channel for python3.5,
so it seems safe to remove it.