Make scan_non_zero_values_fast scan entirely forwards (#1332)

Presently the `forwards` argument to `ranges::break_bit_range` is false,
causing the function to scan the last bits, then the middle bytes, then
the first bits. The argument should be true, so that the function scans
the first bits first.

Author: no-defun-allowed

src/util/metadata/side_metadata/global.rs

@@ -1234,7 +1234,7 @@ impl SideMetadataSpec {
             start_meta_shift,
             end_meta_addr,
             end_meta_shift,
-            false,
+            true,
             &mut visitor,
         );
     }