nt/inc/inttypes.h [!__MINGW32__]: Include stdint.h. Move the
definition of uintmax_t from here...
nt/inc/stdint.h (uintmax_t): ...to here.
(intptr_t) [!__GNUC__]: New typedef.
nt/inc/stdint.h: New file, to support compilation with tool chains
that do not have stdint.h (e.g. MSVC).
lib/makefile.w32-in: ($(BLD)/md5.$(O)): Added dependency on
$(EMACS_ROOT)/nt/inc/stdint.h.