patch proposal for acinclude.m4 to better support gcc on illumos/smartos

As /usr/bin/ld on illumos doesn't (yet) support --as-needed, this patch
to acinclude.m4 will suppress the LDFLAGS -Wl,-as-needed passed when gcc
is used as the compiler in the "bash bootstrap" command.

This patch assumes that all gcc variants running on illumos (gcc3 and
gcc4) are configured with --without-gnu-ld --with-ld=/usr/bin/ld,
which after brief research, seems typically the case.

This has been tested and seems to work fine on oi_151a7 with gcc47 under
pkgsrc http://pkgsrc.smartos.org/packages/illumos/2012Q3/All

~/src/pgadmin3$ git diff
diff --git a/acinclude.m4 b/acinclude.m4
index e9c5a5d..c964e93 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -684,7 +684,9 @@ AC_DEFUN([SETUP_POSTGRESQL],
                         case "${host}" in
                                 *-apple-darwin*)
                                         ;;
-
+                               *solaris*)
+                                       LDFLAGS="$LDFLAGS"
+                                       ;;
                                 *)
                                         LDFLAGS="$LDFLAGS -Wl,-as-needed"
                                         ;;