Fixed a wrong assumption in configure.in and Include/pyport.h. The is finite function is not called isfinite() but finite(). Sorry, my fault. :)

Python/hypot.c

@@ -2,6 +2,7 @@
 
 #include "Python.h"
 
+#ifndef HAVE_HYPOT
 double hypot(double x, double y)
 {
 	double yx;
@@ -20,3 +21,5 @@ double hypot(double x, double y)
 		return x*sqrt(1.+yx*yx);
 	}
 }
+#endif /* HAVE_HYPOT */
+