Part of SF patch #102409 by jlt63: Cygwin Python DLL and Shared
Extension Patch.
Note: this could use some testing on NeXT, DG/UX, or BeOS, because of
the changes in the Makefile regarding $(LDLIBRARY).
diff --git a/config.h.in b/config.h.in
index 934694a..5c2ac37 100644
--- a/config.h.in
+++ b/config.h.in
@@ -634,3 +634,13 @@
/* Define if you have the ieee library (-lieee). */
#undef HAVE_LIBIEEE
+
+#ifdef __CYGWIN__
+#ifdef USE_DL_IMPORT
+#define DL_IMPORT(RTYPE) __declspec(dllimport) RTYPE
+#define DL_EXPORT(RTYPE) __declspec(dllexport) RTYPE
+#else
+#define DL_IMPORT(RTYPE) __declspec(dllexport) RTYPE
+#define DL_EXPORT(RTYPE) __declspec(dllexport) RTYPE
+#endif
+#endif