Turns out we're pretty good already at init-time work in tailscaled.
The regexp/syntax shows up but it's hard to get rid of that; zstd even
uses regexp. *shrug*
Change-Id: I856aca056dcb7489f5fc22ef07f55f34ddf19bd6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>