These were used in the upstream Go code to fuzz-test the handshake
marshal/unmarshal functions. But we don't do that there so best to
remove them.

(The ClientHello equals function is still used, however, to test DTLS
retransmission.)

Change-Id: I950bdf4f7eefa2bca13c10f5328d2e6c586604e2
Reviewed-on: https://boringssl-review.googlesource.com/5470
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>