Added dxerr8 and dxerr9 libraries.

diff --git a/configure.ac b/configure.ac
index 996a3d7..4630e1a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1530,6 +1530,8 @@
 dlls/dsound/Makefile
 dlls/dsound/tests/Makefile
 dlls/dswave/Makefile
+dlls/dxerr8/Makefile
+dlls/dxerr9/Makefile
 dlls/dxguid/Makefile
 dlls/gdi/Makefile
 dlls/gdi/tests/Makefile