alias_for_import_name():  Dueling compiler warnings ;-)
Squash new warnings from VC 7.1 about mixing signed and
unsigned types in comparisons.  I can see why `len` was
changed to size_t here, but don't see why `i` was also
changed.  Change `i` back to int.
diff --git a/Python/ast.c b/Python/ast.c
index 9b32f8b..94fc9e8 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -2030,7 +2030,8 @@
                 return alias(NEW_IDENTIFIER(CHILD(n, 0)), NULL, c->c_arena);
             else {
                 /* Create a string of the form "a.b.c" */
-                size_t i, len;
+				int i;
+                size_t len;
                 char *s;
 
                 len = 0;