Treat handshake_failure in response to ClientHello special.

Add a dedicated error code to the queue for a handshake_failure alert in
response to ClientHello. This matches NSS's client behavior and gives a better
error on a (probable) failure to negotiate initial parameters.

BUG=https://crbug.com/446505

Change-Id: I34368712085a6cbf0031902daf2c00393783d96d
Reviewed-on: https://boringssl-review.googlesource.com/2751
Reviewed-by: Adam Langley <agl@google.com>
4 files changed