[builtins] suppress builtin PGO warnings

Bug: v8:13119
Change-Id: Idbacfe1fd8259a8ff378ec97c770cc997c0c813d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3792606Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82083}

src/compiler/pipeline.cc

@@ -3114,8 +3114,11 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
 
   if (profile_data != nullptr &&
       profile_data->hash() != graph_hash_before_scheduling) {
-    PrintF("Rejected profile data for %s due to function change\n", debug_name);
-    PrintF("Please use tools/builtins-pgo/generate.py to refresh it.\n");
+    if (FLAG_warn_about_builtin_profile_data) {
+      PrintF("Rejected profile data for %s due to function change\n",
+             debug_name);
+      PrintF("Please use tools/builtins-pgo/generate.py to refresh it.\n");
+    }
     profile_data = nullptr;
     data.set_profile_data(profile_data);
   }

src/compiler/scheduler.cc

@@ -495,7 +495,8 @@ class CFGBuilder : public ZoneObject {
         break;
     }
 
-    if (hint_from_profile != BranchHint::kNone &&
+    if (FLAG_warn_about_builtin_profile_data &&
+        hint_from_profile != BranchHint::kNone &&
         BranchHintOf(branch->op()) != BranchHint::kNone &&
         hint_from_profile != BranchHintOf(branch->op())) {
       PrintF("Warning: profiling data overrode manual branch hint.\n");

src/flags/flag-definitions.h

@@ -927,6 +927,9 @@ DEFINE_IMPLICATION(turbo_profiling_verbose, turbo_profiling)
 DEFINE_BOOL(turbo_profiling_log_builtins, false,
             "emit data about basic block usage in builtins to v8.log (requires "
             "that V8 was built with v8_enable_builtins_profiling=true)")
+DEFINE_BOOL(
+    warn_about_builtin_profile_data, false,
+    "flag for mksnapshot, emit warnings when applying builtin profile data")
 DEFINE_BOOL(turbo_verify_allocation, DEBUG_BOOL,
             "verify register allocation in TurboFan")
 DEFINE_BOOL(turbo_move_optimization, true, "optimize gap moves in TurboFan")