The changes of 2144ca38d2 (Get rid of CppUnit boilerplate in
DynamicLibraryTestCase, 2022-04-17) accidentally undid the workaround
from 054cb35b39 (Workaround for a crash with gcc 9.1 from MSYS2 MinGW
32bit, 2019-08-03), so work around the same problem again by avoiding
using CHECK() with function pointers.