Tru64 UNIX 4.0D, with the DTK (Desktop Toolkit), includes int64_t in
/usr/include.dtk/stdint.h.
       
$ gmake
...
(cd openbsd-compat && gmake)
gmake[1]: Entering directory
`/opt/build/openssh-3.2.3p1/openbsd-compat'
cc -O2 -std -I/opt/TWWfsw/tcpwrap/include -I. -I.. -I. -I./..
-I/opt/TWWfsw/libopenssl09s/include -I/opt/TWWfsw/zlib11s/include
-DHAVE_CONFIG_H -c bsd-arc4random.c
cc: Error: ../defines.h, line 151: In this declaration, "uint8_t"
appears to be used as if it named a type, but there is no declared
type of that name visible. (typedefnotdef)
typedef uint8_t u_int8_t;
--------^
cc: Error: ../defines.h, line 152: In this declaration, "uint16_t"
appears to be used as if it named a type, but there is no declared
type of that name visible. (typedefnotdef)
typedef uint16_t u_int16_t;
--------^

The patch below fixes this. This patch was inspired by one from Tim
Mooney:
  http://marc.theaimsgroup.com/?l=openssh-unix-dev&m=99842334021906&w=2

ftp://ftp.thewrittenword.com/outgoing/pub/openssh-3.2.3p1-3.patch