This is prefactoring for a coming change to the shim that will write
handoff and handback messages (which are serialized SSLConnection
objects) to the transcript.

This breaks the slightly tenuous ordering between the runner and the
shim. Fix the runner to wait until the shim has exited before
appending the transcript.

Change-Id: Iae34d28ec1addfe3ec4f3c77008248fe5530687c
Reviewed-on: https://boringssl-review.googlesource.com/27184
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

Bug: 124
Change-Id: Iff02be9df2806572e6d3f860b448f598f85778c3
Reviewed-on: https://boringssl-review.googlesource.com/20107
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

This is getting to be a nuisance to do by hand.

Change-Id: If3aa7c666c4cc0bf97615564f258ff740a561766
Reviewed-on: https://boringssl-review.googlesource.com/12281
Reviewed-by: David Benjamin <davidben@google.com>