configure: Build hashtable for Xres and glvnd
With autoconf, hashtable support is built along with Xres support.
Yet, glvnd also use it, so when disabling Xres from configure, the build will fail at link time because hashtable functions are not available.
Untie the build of hashtable from Xres support, just like meson build does.
Signed-off-by: Olivier Fourdan ofourdan@redhat.com Closes: #1091 (closed)