Reland: ScopeInfo, SharedFunctionInfo never-ever serialized

This relands squashed CLs:

59b9aaf7
8f84d0bb

The revert was at crrev.com/c/2996198.

Changed: Fixed a test in which bytecode flushing caused a behavioral
change between serialized- and unserialized SFI Refs. The serialized
SFI ref kept bytecode alive while unserialized SFIs allow flushing.
The test was fixed by adding a %PrepareFunctionForOptimization
annotation.

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7790, v8:11939
Change-Id: I170f8085bd7454a2a5f2bb03c8824e2862857827
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2999089
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75504}

src/compiler/heap-refs.h

@@ -899,6 +899,8 @@ class V8_EXPORT_PRIVATE SharedFunctionInfoRef : public HeapObjectRef {
   int context_header_size() const;
   BytecodeArrayRef GetBytecodeArray() const;
   SharedFunctionInfo::Inlineability GetInlineability() const;
+  base::Optional<FunctionTemplateInfoRef> function_template_info() const;
+  ScopeInfoRef scope_info() const;
 
 #define DECL_ACCESSOR(type, name) type name() const;
   BROKER_SFI_FIELDS(DECL_ACCESSOR)
@@ -907,12 +909,6 @@ class V8_EXPORT_PRIVATE SharedFunctionInfoRef : public HeapObjectRef {
   bool IsInlineable() const {
     return GetInlineability() == SharedFunctionInfo::kIsInlineable;
   }
-
-  void SerializeFunctionTemplateInfo();
-  base::Optional<FunctionTemplateInfoRef> function_template_info() const;
-
-  void SerializeScopeInfoChain();
-  ScopeInfoRef scope_info() const;
 };
 
 class StringRef : public NameRef {

src/compiler/serializer-for-background-compilation.cc

@@ -1783,12 +1783,6 @@ void SerializerForBackgroundCompilation::VisitForInPrepare(
 
 void SerializerForBackgroundCompilation::ProcessCreateContext(
     interpreter::BytecodeArrayIterator* iterator, int scopeinfo_operand_index) {
-  Handle<ScopeInfo> scope_info =
-      Handle<ScopeInfo>::cast(iterator->GetConstantForIndexOperand(
-          scopeinfo_operand_index, broker()->isolate()));
-  ScopeInfoRef scope_info_ref = MakeRef(broker(), scope_info);
-  scope_info_ref.SerializeScopeInfoChain();
-
   Hints const& current_context_hints = environment()->current_context_hints();
   Hints result_hints;
 
@@ -2245,9 +2239,6 @@ void SerializerForBackgroundCompilation::ProcessApiCall(
   if (!target_template_info.has_call_code()) return;
   target_template_info.SerializeCallCode();
 
-  SharedFunctionInfoRef target_ref = MakeRef(broker(), target);
-  target_ref.SerializeFunctionTemplateInfo();
-
   if (target_template_info.accept_any_receiver() &&
       target_template_info.is_signature_undefined()) {
     return;
@@ -2893,8 +2884,6 @@ void SerializerForBackgroundCompilation::ProcessCheckContextExtensions(
     ProcessContextAccess(context_hints, Context::EXTENSION_INDEX, i,
                          kSerializeSlot);
   }
-  SharedFunctionInfoRef shared = MakeRef(broker(), function().shared());
-  shared.SerializeScopeInfoChain();
 }
 
 void SerializerForBackgroundCompilation::ProcessLdaLookupGlobalSlot(

test/mjsunit/es6/map-constructor-entry-side-effect2.js

@@ -9,8 +9,7 @@ function TestMapConstructorEntrySideEffect(ctor) {
   const k1 = {};
   const k2 = {};
   let callCount = 0;
-  const input = [
-    Object.defineProperty([, 1], "0", {
+  let prop = {
     get() {
       // Verify continuation retains original set function
       ctor.prototype.set = () => {
@@ -18,7 +17,10 @@ function TestMapConstructorEntrySideEffect(ctor) {
       };
       return k1;
     }
-    }),
+  };
+  %PrepareFunctionForOptimization(prop.get);  // To prevent flushing.
+  const input = [
+    Object.defineProperty([, 1], "0", prop),
     [k2, 2]
   ];
   const col = new ctor(input);