Put back the extern declaration for strdup(), between #ifndef MS_WINDOWS.
This should make everybody happy, especially since we don't say what
the argument type is (there is disagreement on that, too :-( ).
diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c
index 6c885df..75b929b 100644
--- a/Modules/parsermodule.c
+++ b/Modules/parsermodule.c
@@ -26,6 +26,9 @@
/* ISTERMINAL() / ISNONTERMINAL() */
#include "compile.h" /* PyNode_Compile() */
+#ifndef MS_WINDOWS
+char *strdup();
+#endif
/* String constants used to initialize module attributes.
*