* symfile.c: Define two new hooks for symbol reading: "pre_add_symbol_hook"

and "post_add_symbol_hook". These hooks are called before we begin reading
        symbols, and after we finish.
        (generic_load): Use new symbol reading hooks and get rid of compiler warning.
        * gdbtk.c (gdbtk_init): Add hooks for pre- and post-symbol reading.
        (gdbtk_pre_add_symbol): New function: the pre-add-symbol hook.
        (gdbtk_post_add_symbol): New function: the post-add-symbol hook.
        (find_file_in_dir): New function. Moved the guts of gdb_find_file_command
        into here to allow its use by others.
        (gdb_loc): Use find_file_in_dir to return the real path to the file
        (or "N/A" if we can't find it).
        * configure.in (TIX_LIB_EXT): Define new variable for those special cases
        when TCL_SHLIB_SUFFIX is not enough to specify the dependency.
        * configure: Regenerate.

gdb/configure.in

@@ -361,9 +361,18 @@ if test "${enable_gdbtk}" = "yes"; then
 	   esac 
 	   if test "${TCL_SHARED_BUILD}" = "1"; then
 		TIX_LIB_EXT="${TCL_SHLIB_SUFFIX}"
+
+	        # Can't win them all: SunOS 4 (others?) appends a version
+                # number after the ".so"
+	        case "${host}" in
+	        *-*-sunos4*)
+	            TIX_LIB_EXT="${TIX_LIB_EXT}.1.0" ;;
+                esac
+	   
 	   else
 		TIX_LIB_EXT=".a"
 	   fi
+
 	   if test "${TCL_LIB_VERSIONS_OK}" = "ok"; then
 		TIXLIB="-L${tixdir} -ltix${TIXVERSION}"
 		TIX_DEPS="${tixdir}/libtix${TIXVERSION}${TIX_LIB_EXT}"