LibJS: Rename Environment Records so they match the spec :^)

This patch makes the following name changes:

- ScopeObject => EnvironmentRecord
- LexicalEnvironment => DeclarativeEnvironmentRecord
- WithScope => ObjectEnvironmentRecord

Userland/Libraries/LibJS/Runtime/DeclarativeEnvironmentRecord.cpp

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Interpreter.h>
+#include <LibJS/Runtime/DeclarativeEnvironmentRecord.h>
+#include <LibJS/Runtime/Error.h>
+#include <LibJS/Runtime/Function.h>
+#include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/Value.h>
+
+namespace JS {
+
+DeclarativeEnvironmentRecord::DeclarativeEnvironmentRecord()
+    : EnvironmentRecord(nullptr)
+{
+}
+
+DeclarativeEnvironmentRecord::DeclarativeEnvironmentRecord(EnvironmentRecordType environment_record_type)
+    : EnvironmentRecord(nullptr)
+    , m_environment_record_type(environment_record_type)
+{
+}
+
+DeclarativeEnvironmentRecord::DeclarativeEnvironmentRecord(HashMap<FlyString, Variable> variables, EnvironmentRecord* parent_scope)
+    : EnvironmentRecord(parent_scope)
+    , m_variables(move(variables))
+{
+}
+
+DeclarativeEnvironmentRecord::DeclarativeEnvironmentRecord(HashMap<FlyString, Variable> variables, EnvironmentRecord* parent_scope, EnvironmentRecordType environment_record_type)
+    : EnvironmentRecord(parent_scope)
+    , m_environment_record_type(environment_record_type)
+    , m_variables(move(variables))
+{
+}
+
+DeclarativeEnvironmentRecord::~DeclarativeEnvironmentRecord()
+{
+}
+
+void DeclarativeEnvironmentRecord::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_this_value);
+    visitor.visit(m_home_object);
+    visitor.visit(m_new_target);
+    visitor.visit(m_current_function);
+    for (auto& it : m_variables)
+        visitor.visit(it.value.value);
+}
+
+Optional<Variable> DeclarativeEnvironmentRecord::get_from_scope(const FlyString& name) const
+{
+    return m_variables.get(name);
+}
+
+void DeclarativeEnvironmentRecord::put_to_scope(const FlyString& name, Variable variable)
+{
+    m_variables.set(name, variable);
+}
+
+bool DeclarativeEnvironmentRecord::delete_from_scope(FlyString const& name)
+{
+    return m_variables.remove(name);
+}
+
+bool DeclarativeEnvironmentRecord::has_super_binding() const
+{
+    return m_environment_record_type == EnvironmentRecordType::Function && this_binding_status() != ThisBindingStatus::Lexical && m_home_object.is_object();
+}
+
+Value DeclarativeEnvironmentRecord::get_super_base()
+{
+    VERIFY(has_super_binding());
+    if (m_home_object.is_object())
+        return m_home_object.as_object().prototype();
+    return {};
+}
+
+bool DeclarativeEnvironmentRecord::has_this_binding() const
+{
+    // More like "is_capable_of_having_a_this_binding".
+    switch (m_environment_record_type) {
+    case EnvironmentRecordType::Declarative:
+    case EnvironmentRecordType::Object:
+        return false;
+    case EnvironmentRecordType::Function:
+        return this_binding_status() != ThisBindingStatus::Lexical;
+    case EnvironmentRecordType::Module:
+        return true;
+    }
+    VERIFY_NOT_REACHED();
+}
+
+Value DeclarativeEnvironmentRecord::get_this_binding(GlobalObject& global_object) const
+{
+    VERIFY(has_this_binding());
+    if (this_binding_status() == ThisBindingStatus::Uninitialized) {
+        vm().throw_exception<ReferenceError>(global_object, ErrorType::ThisHasNotBeenInitialized);
+        return {};
+    }
+    return m_this_value;
+}
+
+void DeclarativeEnvironmentRecord::bind_this_value(GlobalObject& global_object, Value this_value)
+{
+    VERIFY(has_this_binding());
+    if (m_this_binding_status == ThisBindingStatus::Initialized) {
+        vm().throw_exception<ReferenceError>(global_object, ErrorType::ThisIsAlreadyInitialized);
+        return;
+    }
+    m_this_value = this_value;
+    m_this_binding_status = ThisBindingStatus::Initialized;
+}
+
+}