Add test for renego client_version quirk.

In upstream's f4e1169341ad1217e670387db5b0c12d680f95f4, the client_version was
made constant across renegotiations, even if the server negotiated a lower
version. NSS has the same quirk, reportedly for SChannel:

https://code.google.com/p/chromium/codesearch#chromium/src/net/third_party/nss/ssl/ssl3con.c&sq=package:chromium&l=5103

Add a test to ensure we do not regress this.

Change-Id: I214e062463c203b86a9bab00f8503442e1bf74fe
Reviewed-on: https://boringssl-review.googlesource.com/2405
Reviewed-by: Adam Langley <agl@google.com>
5 files changed