Suppress compiler warnings for signed/unsigned comparisons.

BTrees/BucketTemplate.c

@@ -1836,7 +1836,7 @@ bucket_repr(Bucket *self)
                        "%s(%s)", Py_TYPE(self)->tp_name,
                        PyBytes_AS_STRING(r));
 #endif
-    if (rv > 0 && rv < sizeof(repr))
+    if (rv > 0 && (size_t)rv < sizeof(repr))
     {
         Py_DECREF(r);
 #ifdef PY3K

BTrees/sorters.c

@@ -93,7 +93,7 @@ radixsort_int(element_type *in, element_type *work, size_t n)
 	int offset, offsetinc;
 
 	/* Which byte position are we working on now?  0=LSB, 1, 2, ... */
-	int bytenum;
+	size_t bytenum;
 
 #ifdef ZODB_64BIT_INTS
 	assert(sizeof(element_type) == 8);