libpq.so linking problem on Solaris using --with-gssapi

When building PostgreSQL 8.3 on Solaris using the configure option
"--with-gssapi", libpq.so is not linked correctly.

This line in the libpq Makefile is selecting the appropriate linker
options:

---
SHLIB_LINK += $(filter -lcrypt -ldes -lcom_err -lcrypto -lk5crypto -lkrb5 -lgssapi_krb5 -lssl -lsocket -lnsl -lresolv
-lintl,$(LIBS)) $(LDAP_LIBS_FE) $(PTHREAD_LIBS) 
---

This includes "-lgssapi_krb5", but for Solaris this should be just
"-lgss".

The result is that libpq.so does not load libgss.so.  psql still works
because it apparently loads libgss.so before it loads libpq.so, otherwise
it would surely have been discovered earlier.

But when I tried to run a test for the TCL client interface I got:

---
TCL test status: Started
couldn't load file "libpgtcl1.5.so": ld.so.1: tclsh8.4: fatal: relocation error: file <....>/lib/libpq.so.5: symbol
GSS_C_NT_HOSTBASED_SERVICE:referenced symbol not found 
    while executing
"load libpgtcl1.5.so"
    (file "./import_sampledata.tcl" line 7)
---

This could affect other clients too.

The fix is simply to add "-lgss" to the list, as the attached patch
does.  I'm pretty sure no other Makefiles are affected.

Tested on Solaris (x86 and sparc), and also Linux (RHEL 5).

I plan to apply this patch when I integrate 8.3.0 into OpenSolaris.

--
Bjorn Munch
Database Technology Group
Sun Microsystems