LibJS: Move ExecutionContext::context_owner to rare data

This is only used by ExecutionContexts owned by an HTML::ESO.

Author: awesomekling

Libraries/LibJS/Runtime/ExecutionContext.cpp

@@ -144,7 +144,6 @@ void ExecutionContext::visit_edges(Cell::Visitor& visitor)
     visitor.visit(variable_environment);
     visitor.visit(lexical_environment);
     visitor.visit(private_environment);
-    visitor.visit(context_owner);
     visitor.visit(cached_source_range);
     visitor.visit(m_rare_data);
     if (this_value.has_value())
@@ -161,6 +160,7 @@ void ExecutionContext::visit_edges(Cell::Visitor& visitor)
 void ExecutionContextRareData::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
+    visitor.visit(context_owner);
     for (auto& context : unwind_contexts) {
         visitor.visit(context.lexical_environment);
     }
@@ -170,7 +170,7 @@ void ExecutionContextRareData::visit_edges(Cell::Visitor& visitor)
 GC::Ref<ExecutionContextRareData> ExecutionContext::ensure_rare_data()
 {
     if (!m_rare_data) {
-        m_rare_data = executable->heap().allocate<ExecutionContextRareData>();
+        m_rare_data = GC::Heap::the().allocate<ExecutionContextRareData>();
     }
     return *m_rare_data;
 }

Libraries/LibJS/Runtime/ExecutionContext.h

@@ -36,7 +36,7 @@ class CachedSourceRange final : public GC::Cell {
     Variant<UnrealizedSourceRange, SourceRange> source_range;
 };
 
-class ExecutionContextRareData final : public GC::Cell {
+class JS_API ExecutionContextRareData final : public GC::Cell {
     GC_CELL(ExecutionContextRareData, GC::Cell);
     GC_DECLARE_ALLOCATOR(ExecutionContextRareData);
 
@@ -45,6 +45,9 @@ class ExecutionContextRareData final : public GC::Cell {
     Vector<Optional<size_t>> previously_scheduled_jumps;
     Vector<GC::Ptr<Environment>> saved_lexical_environments;
 
+    // Non-standard: This points at something that owns this ExecutionContext, in case it needs to be protected from GC.
+    GC::Ptr<Cell> context_owner;
+
 private:
     virtual void visit_edges(Cell::Visitor&) override;
 };
@@ -82,9 +85,6 @@ struct JS_API ExecutionContext {
     Span<Value> registers_and_constants_and_locals_arguments;
     ReadonlySpan<Utf16FlyString> identifier_table;
 
-    // Non-standard: This points at something that owns this ExecutionContext, in case it needs to be protected from GC.
-    GC::Ptr<Cell> context_owner;
-
     u32 program_counter { 0 };
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#skip-when-determining-incumbent-counter

Libraries/LibWeb/HTML/Scripting/Environments.cpp

@@ -38,7 +38,7 @@ void Environment::visit_edges(Cell::Visitor& visitor)
 EnvironmentSettingsObject::EnvironmentSettingsObject(NonnullOwnPtr<JS::ExecutionContext> realm_execution_context)
     : m_realm_execution_context(move(realm_execution_context))
 {
-    m_realm_execution_context->context_owner = this;
+    m_realm_execution_context->ensure_rare_data()->context_owner = this;
 
     // Register with the responsible event loop so we can perform step 4 of "perform a microtask checkpoint".
     responsible_event_loop().register_environment_settings_object({}, *this);