Add scavenger chaos mode to Fuzzilli

Bug: 450045070
Change-Id: I6bf07aa3b854e703b0b199939e8e9018a1ef00a7
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8690756
Reviewed-by: Matthias Liedtke <mliedtke@google.com>
Commit-Queue: Omer Katz <omerkatz@google.com>

Author: omerktz

Sources/FuzzilliCli/Profiles/V8Profile.swift

@@ -127,6 +127,12 @@ let v8Profile = Profile(
             args.append("--handle-weak-ref-weakly-in-minor-gc")
         }
 
+        if probability(0.1) {
+            args.append("--scavenger-chaos-mode")
+            let threshold = Int.random(in: 0...100)
+            args.append("--scavenger-chaos-mode-threshold=\(threshold)")
+        }
+
         if probability(0.1) {
             let stackSize = Int.random(in: 54...863)
             args.append("--stack-size=\(stackSize)")