Preparse inner functions: fix maybe_assigned

... but be less pessimistic about context allocation (see below).

We might have just (pessimistically) context-allocated a variable based
on references coming from an inner function, but after that we still
need to set maybe_assigned (pessimistically).

This makes test-parsing/InnerAssignment pass with
FLAG_lazy_inner_functions.

This was undetected until now because we didn't have lazy parsing enabled
for small scripts.

Less pessimistic approach: now that inner functions laziness decisions
are stable (if we have once compiled a piece of code with lazy inner
functions, we never compile the same code with eager inner functions),
we don't need to be as pessimistic with context allocation as before.

BUG=v8:5501

Review-Url: https://codereview.chromium.org/2521513004
Cr-Commit-Position: refs/heads/master@{#41183}

src/ast/scopes.cc

@@ -1609,29 +1609,6 @@ void Scope::ResolveVariable(ParseInfo* info, VariableProxy* proxy) {
   DCHECK(!proxy->is_resolved());
   Variable* var = LookupRecursive(proxy, nullptr);
   ResolveTo(info, proxy, var);
-
-  if (FLAG_lazy_inner_functions) {
-    if (info != nullptr && info->is_native()) return;
-    // Pessimistically force context allocation for all variables to which inner
-    // scope variables could potentially resolve to.
-    Scope* scope = GetClosureScope()->outer_scope_;
-    while (scope != nullptr && scope->scope_info_.is_null()) {
-      var = scope->LookupLocal(proxy->raw_name());
-      if (var != nullptr) {
-        // Since we don't lazy parse inner arrow functions, inner functions
-        // cannot refer to the outer "this".
-        if (!var->is_dynamic() && !var->is_this() &&
-            !var->has_forced_context_allocation()) {
-          var->ForceContextAllocation();
-          var->set_is_used();
-          // We don't know what the (potentially lazy parsed) inner function
-          // does with the variable; pessimistically assume that it's assigned.
-          var->set_maybe_assigned();
-        }
-      }
-      scope = scope->outer_scope_;
-    }
-  }
 }
 
 namespace {

src/parsing/preparser.cc

@@ -266,8 +266,11 @@ PreParserExpression PreParser::ExpressionFromIdentifier(
     // AstValueFactory doesn't know about it.
     factory.set_zone(zone());
     DCHECK_NOT_NULL(name.string_);
-    scope()->NewUnresolved(&factory, name.string_, start_position,
-                           NORMAL_VARIABLE);
+    VariableProxy* proxy = scope()->NewUnresolved(
+        &factory, name.string_, start_position, NORMAL_VARIABLE);
+    // We don't know whether the preparsed function assigns or not, so we set
+    // is_assigned pessimistically.
+    proxy->set_is_assigned();
   }
   return PreParserExpression::FromIdentifier(name, zone());
 }