6.5 make error on Solaris 2.5.1

Hi, I tried to compile v6.5 on Solaris 2.5.1 and got following
error.

OS : Sun Solaris 2.5.1 (Sparc)
gcc : 2.8.1
gmake : 3.75
configure option : none
 * * *
gcc -o ecpg preproc.o pgc.o type.o ecpg.o ecpg_keywords.o ../../../backend/parser/scansup.o keywords.o c_keywords.o
../lib/typename.o -lgen -lcrypt -lnsl -lsocket -ldl -lm -ltermcap -lcurses  
gmake[3]: Leaving directory `/usr/local/src/postgresql-6.5/src/interfaces/ecpg/preproc'
gmake[2]: Leaving directory `/usr/local/src/postgresql-6.5/src/interfaces/ecpg'
gmake -C libpq++ all
gmake[2]: Entering directory `/usr/local/src/postgresql-6.5/src/interfaces/libpq++'
c++  -I../../backend -I../../include -I../../interfaces/libpq -I../../include -I../../backend    -Wall
-Wmissing-prototypes-fPIC   -c pgconnection.cc -o pgconnection.o 
In file included from /usr/local/include/g++/streambuf.h:36,
                 from /usr/local/include/g++/iostream.h:31,
                 from /usr/local/include/g++/stl_alloc.h:45,
                 from /usr/local/include/g++/alloc.h:21,
                 from /usr/local/include/g++/std/bastring.h:39,
                 from /usr/local/include/g++/string:6,
                 from pgconnection.h:24,
                 from pgconnection.cc:20:
/usr/local/include/g++/libio.h:59: sys/cdefs.h: No such file or directory
gmake[2]: *** [pgconnection.o] Error 1
gmake[2]: Leaving directory `/usr/local/src/postgresql-6.5/src/interfaces/libpq++'
gmake[1]: *** [all] Error 2
gmake[1]: Leaving directory `/usr/local/src/postgresql-6.5/src/interfaces'
gmake: *** [all] Error 2
 * * *
Actually sys/cdefs.h doesn't exist on my system.

Is there any basic difficulty to run 6.5 on Solaris 2.5.1 ?
or am I missing something ?
======================================================================
Keizo SHIMIZU
Solution Business Support Group, Network Service Center,
Open System Business Organization, Nissho Electronics Corporation
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TEL    : +81 3 3544 8469         FAX    : +81 3 3544 8260
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