Even more ANSIfication: fix as many function pointers and declarations as
possible.
diff --git a/Modules/getpath.c b/Modules/getpath.c
index 3c418d6..f96f7ed 100644
--- a/Modules/getpath.c
+++ b/Modules/getpath.c
@@ -349,7 +349,7 @@
 static void
 calculate_path(void)
 {
-    extern char *Py_GetProgramName();
+    extern char *Py_GetProgramName(void);
 
     static char delimiter[2] = {DELIM, '\0'};
     static char separator[2] = {SEP, '\0'};