The current order results in compiler warnings on 32 bit machines, e.g.

src/llfuse.c: In function '__Pyx_PyInt_TrueDivideObjC':
src/llfuse.c:43980:17: warning: left shift count >= width of type
                 if (8 * sizeof(long) <= 53 || (__Pyx_sst_abs(size) <= 52 / PyLong_SHIFT) || likely(labs(a) <= (1L << 53))) {

Switching the order so that the left shift is closer to the sizeof test
avoids the warning, presumably because it makes it easier for the
compiler to see that the left shift is only executed on 64 bit.

Thanks to Christian Neukirchen for doing most of the work!

This solves the issue reported by Volker Braun where conflicting
using aliases of uint64_t would result in compile time errors.

Unfortunately, this also means that it's always included if
CYTHON_USE_PYLONG_INTERNALS is set, but it's a short header.