configure.in thread support for Solaris

[openldap-devel@thewrittenword.com]

Is it possible to check for thread support functions in $LIBS last
rather than first? Running configure "out of the box" on Solaris
will cause the check for pthread_create in $LIBS to succeed
(because it is in libc) but the check later on to test if
pthread.h and pthread_create are compatible will fail (because
the sample C program is not linked with -lpthread). Guy Matz
gets around this by setting LIBS="-lpthread -lposix4" prior
to configure but it really should not be necessary.

-- 
albert chin (china@thewrittenword.com)