This reverts commit 101fd4dd.

Reason for revert: Uncaught exception in the recipe API https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux/29928

Original change's description:
> [testrunner] catch unforeseen exceptions
> 
> Testrunner doesn't catch exceptions except TestRunnererror, KeyboardInterrupt.
> 
> Unforeseen exceptions should fail the CI step.
> 
> This CL returns an error exit code for uncaught exceptions.
> 
> R=​machenbach@chromium.org
> CC=​yangguo@chromium.org,sergiyb@chromium.org
> 
> Bug: v8:8731
> Change-Id: I7fb20dad4a3eea29f1dfa87ef91d45381ee08692
> Reviewed-on: https://chromium-review.googlesource.com/c/1434034
> Commit-Queue: Tamer Tas <tmrts@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59278}

TBR=machenbach@chromium.org,tmrts@chromium.org

Change-Id: Ia2b661c1a71d1799693383bc942a9a1d47668b24
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8731
Reviewed-on: https://chromium-review.googlesource.com/c/1449692Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59282}