NewContainsIPFunc returns a contains matcher optimized for its
input. Use that instead of what this did before, always doing a test
over each of a list of netip.Prefixes.
goos: darwin
goarch: arm64
pkg: tailscale.com/wgengine/filter
│ before │ after │
│ sec/op │ sec/op vs base │
FilterMatch/file1-8 32.60n ± 1% 18.87n ± 1% -42.12% (p=0.000 n=10)
Updates #12486
Change-Id: I8f902bc064effb431e5b46751115942104ff6531
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
21ed31e33a