Bug 395586 - Make xulrunner debug build libxul still.

r=ted.mielczarek@gmail.com (Ted Mielczarek)
a=bzbarsky@mit.edu (Boris Zbarsky)

configure.in

@@ -6762,8 +6762,8 @@ MOZ_ARG_ENABLE_BOOL(static,
     BUILD_STATIC_LIBS=1,
     BUILD_STATIC_LIBS=)
 
-dnl Disable libxul in debug builds.
-if test -n "$MOZ_DEBUG"; then
+dnl Disable libxul in debug builds, but not for xulrunner.
+if test -n "$MOZ_DEBUG" -a "$MOZ_BUILD_APP" != "xulrunner"; then
    MOZ_ENABLE_LIBXUL=
 fi