Solaris 10 fails to configure

[anonymous]

Addition to ticket 537 from config.log

configure:27969: checking for off_t
configure:28023: result: yes
configure:28026: checking size of off_t
configure:28345: gcc -o conftest -g -O2 -D_XOPEN_SOURCE=600 -D_BSD_SOURCE  -D_REENTRANT -D__EXTENSIONS__ -I/usr/local/include -D_FILE_OFFSET_BITS=64
 -D_LARGEFILE_SOURCE -D_LARGE_FILES  conftest.c -lresolv -lnsl -lsocket  >&5
In file included from /usr/include/iso/stdarg_c99.h:34,
                 from /usr/include/stdarg.h:33,
                 from /usr/sfw/lib/gcc/sparc-sun-solaris2.10/3.4.3/include/stdio.h:14,
                 from conftest.c:79:
/usr/include/sys/feature_tests.h:336:2: #error "Compiler or options invalid; UNIX 03 and POSIX.1-2001 applications      require the use of c99"
configure:28348: $? = 1
configure: program exited with status 1
configure: failed program was:
| /* confdefs.h.  */

[conny]

see #537. (Increased spamming sadly seems to have forced the disabling of anonymous comments...)