gcc warns about this:

../wine/dlls/ntdll/unix/virtual.c: In function ‘mmap_add_reserved_area’:
../wine/dlls/ntdll/unix/virtual.c:241:9: error: the comparison will always evaluate as ‘true’ for the pointer operand in ‘(char *)addr + (sizetype)size’ must not be NULL [-Werror=address]
  241 |     if (!((char *)addr + size)) size--;  /* avoid wrap-around */
      |         ^