[v8] Add --proto_assign_seq_lazy_func_opt and --private_field_bytecodes

Include `--private_field_bytecodes` with a 0.5 probability.

Include `--proto_assign_seq_lazy_func_opt` with a 0.5 probability in
fuzzili. This flag does imply the flag it replaces. Seq count is fixed
to 1 to stress the pattern.

Bug: 449885256
Bug: 474269456
Change-Id: I4e9928c2c3b23ebc129bfae67d06dc286a8dfba7
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/9095116
Reviewed-by: Michael Achenbach <machenbach@google.com>
Reviewed-by: Matthias Liedtke <mliedtke@google.com>
Commit-Queue: Raphaël Hérouart <rherouart@google.com>

Author: rherouart-collab

Sources/Fuzzilli/Profiles/V8CommonProfile.swift

@@ -1027,12 +1027,16 @@ public func v8ProcessArgs(randomize: Bool, forSandbox: Bool) -> [String] {
     }
 
     if probability(0.5) {
-        args.append("--proto-assign-seq-opt")
+        args.append("--proto-assign-seq-lazy-func-opt")
         if probability(0.5) {
             args.append("--proto-assign-seq-opt-count=1")
         }
     }
 
+    if probability(0.5) {
+        args.append("--private-field-bytecodes")
+    }
+
     //
     // Sometimes enable additional verification/stressing logic (which may be fairly expensive).
     //