Build: Add a comment to configure.ac about symbol versioning.
diff --git a/configure.ac b/configure.ac
index 25eb838..0941e8e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -414,6 +414,10 @@
[], [enable_symbol_versions=auto])
if test "x$enable_symbol_versions" = xauto; then
case $host_os in
+ # NOTE: Even if one omits -gnu on GNU/Linux (e.g.
+ # i486-slackware-linux), configure will (via config.sub)
+ # append -gnu (e.g. i486-slackware-linux-gnu), and this
+ # test will work correctly.
gnu* | *-gnu* | freebsd*)
enable_symbol_versions=yes
;;
