Patch #734231: Update RiscOS support. In particular, correct
riscospath.extsep, and use os.extsep throughout.
diff --git a/Python/compile.c b/Python/compile.c
index ba8b945..805c519 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -420,7 +420,7 @@
 			goto exitUnchanged;
 		}
 	}
-	code = PyString_FromStringAndSize(codestr, codelen);
+	code = PyString_FromStringAndSize((char *)codestr, codelen);
 	PyMem_Free(codestr);
 	return code;