Make sure Win32 platform config is read and that we know

multithreading is enabled (when it is).


[SVN r20003]

tools/build

@@ -1 +1 @@
-Subproject commit 99185d75eb636bd897b382bddfd9bab33310a72d
+Subproject commit 75b7081712612e08426b842baca5db6fa20a33a9