[foozzie] Add more stress experiments

NOTRY=true

Bug: v8:8278
Change-Id: I0f6c5ca3766ce6a9ffa2a97082b875b2a3fb357f
Reviewed-on: https://chromium-review.googlesource.com/c/1450122Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59326}

tools/clusterfuzz/v8_foozzie.py

@@ -78,6 +78,11 @@ ADDITIONAL_FLAGS = [
   (0.1, '--stress-compaction-random'),
   (0.1, '--random-gc-interval=2000'),
   (0.2, '--noanalyze-environment-liveness'),
+  (0.1, '--stress-delay-tasks'),
+  (0.01, '--thread-pool-size=1'),
+  (0.01, '--thread-pool-size=2'),
+  (0.01, '--thread-pool-size=4'),
+  (0.01, '--thread-pool-size=8'),
 ]
 
 # Timeout in seconds for one d8 run.