Changes provided by Landry Breuil to make it compile on OpenBSD.
See https://bugzilla.mozilla.org/show_bug.cgi?id=844430
diff --git a/configure.ac b/configure.ac
index 639c888..0ca13c6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -53,6 +53,10 @@
   fi
   LIBCFLAGS="$LIBCFLAGS -U__FreeBSD__ -D__Userspace_os_FreeBSD"
   ;;
+openbsd*)
+  CFLAGS="$CFLAGS -pedantic -Wall -Werror -pthread"
+  LIBCFLAGS="$LIBCFLAGS -U__OpenBSD__ -D__Userspace_os_OpenBSD"
+  ;;
 solaris*)
   CFLAGS="$CFLAGS -D_XPG4_2"
   ;;