poly1305: add burn-in test.

This is the test that I use to sanity-check significant changes to the
package, thus it's probably worth checking it in. Since it's very slow,
it's disabled by default.

(Note that while it stands a good chance of catching errors in 32-bit
implementations, no amount of random testing is going to get useful
coverage for 64-bit implementations. Thus it really is just a sanity
check, despite the long run-time.)

Change-Id: I95b321eec6f3026dafbbc157a7ef35a27e88d247
Reviewed-on: https://go-review.googlesource.com/36566
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1 file changed