Squashed compiler warnings by adding casts, making sure prototypes are in
scope and looking at types.
diff --git a/Python/dynload_next.c b/Python/dynload_next.c
index 0b232f1..cf42cb7 100644
--- a/Python/dynload_next.c
+++ b/Python/dynload_next.c
@@ -77,7 +77,7 @@
 		newModule = NSLinkModule(image, pathname, LINKOPTIONS);
 		if (newModule == NULL) {
 			int errNo;
-			char *fileName, *moreErrorStr;
+			const char *fileName, *moreErrorStr;
 			NSLinkEditErrors c;
 			NSLinkEditError( &c, &errNo, &fileName, &moreErrorStr );
 			PyOS_snprintf(errBuf, 512, "Failure linking new module: %s: %s",