Many values stored in the preparse data for the skippable functions
fit in one byte most of the time. The varint encoding uses a single
continue bit per byte to tell whether there is a following byte.

Change-Id: Ia0a622ba42a338fc91eea1e0c1a72d2582d9f867
Reviewed-on: https://chromium-review.googlesource.com/c/1400842
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58972}