Revert of [ast] Simplify FetchFreeVariables. (patchset #1 id:1 of...

Revert of [ast] Simplify FetchFreeVariables. (patchset #1 id:1 of https://codereview.chromium.org/2491373004/ )

Reason for revert:
It's probably needed after all but we're lacking tests.

Original issue's description:
> [ast] Simplify FetchFreeVariables.
>
> This CL removes the ParseInfo argument from FetchFreeVariables, since it seems
> to have become unnecessary.
>
> R=verwaest@chromium.org
> BUG=

TBR=verwaest@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Review-Url: https://codereview.chromium.org/2495293002
Cr-Commit-Position: refs/heads/master@{#40964}

src/ast/scopes.cc

@@ -1247,7 +1247,7 @@ Scope* Scope::GetOuterScopeWithContext() {
 
 Handle<StringSet> DeclarationScope::CollectNonLocals(
     ParseInfo* info, Handle<StringSet> non_locals) {
-  VariableProxy* free_variables = FetchFreeVariables(this, true);
+  VariableProxy* free_variables = FetchFreeVariables(this, true, info);
   for (VariableProxy* proxy = free_variables; proxy != nullptr;
        proxy = proxy->next_unresolved()) {
     non_locals = StringSet::Add(non_locals, proxy->name());
@@ -1734,7 +1734,7 @@ void Scope::ResolveVariablesRecursively(ParseInfo* info) {
 }
 
 VariableProxy* Scope::FetchFreeVariables(DeclarationScope* max_outer_scope,
-                                         bool try_to_resolve,
+                                         bool try_to_resolve, ParseInfo* info,
                                          VariableProxy* stack) {
   for (VariableProxy *proxy = unresolved_, *next = nullptr; proxy != nullptr;
        proxy = next) {
@@ -1747,6 +1747,8 @@ VariableProxy* Scope::FetchFreeVariables(DeclarationScope* max_outer_scope,
     if (var == nullptr) {
       proxy->set_next_unresolved(stack);
       stack = proxy;
+    } else if (info != nullptr) {
+      ResolveTo(info, proxy, var);
     } else {
       var->set_is_used();
     }
@@ -1756,7 +1758,8 @@ VariableProxy* Scope::FetchFreeVariables(DeclarationScope* max_outer_scope,
   unresolved_ = nullptr;
 
   for (Scope* scope = inner_scope_; scope != nullptr; scope = scope->sibling_) {
-    stack = scope->FetchFreeVariables(max_outer_scope, try_to_resolve, stack);
+    stack =
+        scope->FetchFreeVariables(max_outer_scope, try_to_resolve, info, stack);
   }
 
   return stack;

src/ast/scopes.h

@@ -520,8 +520,10 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
 
   // Finds free variables of this scope. This mutates the unresolved variables
   // list along the way, so full resolution cannot be done afterwards.
+  // If a ParseInfo* is passed, non-free variables will be resolved.
   VariableProxy* FetchFreeVariables(DeclarationScope* max_outer_scope,
                                     bool try_to_resolve = true,
+                                    ParseInfo* info = nullptr,
                                     VariableProxy* stack = nullptr);
 
   // Predicates.