Procs return the result by increasing recursion through result_for.

This CL eliminates that mechanism from the Processor interface and uses boolen
return values for sending tests to signal success or the failure to load the
test into the execution queue.

R=machenbach@chromium.org
CC=​​yangguo@chromium.org,sergiyb@chromium.org

Bug: v8:8174,v8:8731
Change-Id: I073a86ca84bcf88da11132b90013d4c8455bc61e
Reviewed-on: https://chromium-review.googlesource.com/c/1439239
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59201}

Timeouts on num-fuzzer only lead to false positives, as tests might
take unpredictably longer.

This CL forgives timeouts through a global override mechanism of the
expected outcomes. This allows to remove already existing scattered
code that allowed timeouts in some test suites only.

Bug: v8:6917
Change-Id: Ib131765d360e335789c1952bc6793ed051e016ea
Reviewed-on: https://chromium-review.googlesource.com/908454
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51188}