Fix MS-Windows build broken by make-fingerprint changes

* lib-src/make-fingerprint.c (fseeko) [WNDOWSNT]: Define to
fseeko64 for non-MinGW64 MinGW.

* lib-src/ntlib.c (stat): Fix calculation of file size.
(fstat): New function, a subset of src/w32.c:fstat.  This is
needed because make-fingerprint.c now calls 'fstat', and the
MS version will fail to produce reliable results because
nt/inc/sys/stat.h redefines 'struct stat'.
1 job for master in 50 minutes and 41 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #1372
test-all

00:50:41

 
Name Stage Failure
failed
test-all Test
Makefile:313: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[1]: *** [check-expensive] Error 2
Makefile:288: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:962: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1