[xml] Module support in 2.6.22

[Albert Chin <libxml mlists thewrittenword com>]

1. Module support is not detected properly on Tru64 UNIX. It
   supports dlopen() but doesn't require -ldl for it.
2. The standard library path on HP-UX is ".sl", not ".so".

-- 
albert chin (china thewrittenword com)

-- snip snip
Index: configure.in
===================================================================
--- configure.in.orig   2005-09-12 16:17:14.000000000 -0500
+++ configure.in        2005-10-27 23:24:56.169272000 -0500
@@ -703,18 +635,34 @@
   ])
   ;;
   *)
-  MODULE_EXTENSION=".so"
-  AC_CHECK_LIB(dld, shl_load, [
+  AC_CHECK_FUNC(shl_load, libxml_have_shl_load=yes, [
+    AC_CHECK_LIB(dld, shl_load, [
+      MODULE_PLATFORM_LIBS="-ldld"
+      libxml_have_shl_load=yes], [
+      AC_CHECK_FUNC(dlopen, libxml_have_dlopen=yes, [
+        AC_CHECK_LIB(dl, dlopen, [
+          MODULE_PLATFORM_LIBS="-ldl"
+          libxml_have_dlopen=yes])])])])
+
+  if test "${libxml_have_shl_load}" = "yes"; then
+    MODULE_EXTENSION=".sl"
     WITH_MODULES=1
-    MODULE_PLATFORM_LIBS="-ldld"
     AC_DEFINE([HAVE_SHLLOAD], [], [Have shl_load based dso])
-  ])
+  fi
  
-  AC_CHECK_LIB(dl, dlopen, [
+  if test "${libxml_have_dlopen}" = "yes"; then
+    case "${host}" in
+      *-*-hpux* )
+       MODULE_EXTENSION=".sl"
+       ;;
+      * )
+       MODULE_EXTENSION=".so"
+       ;;
+    esac
+
     WITH_MODULES=1
-    MODULE_PLATFORM_LIBS="-ldl"
     AC_DEFINE([HAVE_DLOPEN], [], [Have dlopen based dso])
-  ])
+  fi
  ;;
  esac
 fi