LibJS: Bring function environment records closer to the spec

This patch adds FunctionEnvironmentRecord as a subclass of the existing
DeclarativeEnvironmentRecord. Things that are specific to function
environment records move into there, simplifying the base.

Most of the abstract operations related to function environment records
are rewritten to match the spec exactly. I also had to implement
GetThisEnvironment() and GetSuperConstructor() to keep tests working
after the changes, so that's nice as well. :^)

1 files changed, 4 insertions, 4 deletions

diff --git a/Userland/Libraries/LibJS/Interpreter.cpp b/Userland/Libraries/LibJS/Interpreter.cpp
index bc65abdf3c..8779ad23f7 100644
--- a/Userland/Libraries/LibJS/Interpreter.cpp
+++ b/Userland/Libraries/LibJS/Interpreter.cpp
@@ -9,7 +9,7 @@
 #include <AK/StringBuilder.h>
 #include <LibJS/AST.h>
 #include <LibJS/Interpreter.h>
-#include <LibJS/Runtime/DeclarativeEnvironmentRecord.h>
+#include <LibJS/Runtime/FunctionEnvironmentRecord.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Object.h>
 #include <LibJS/Runtime/Reference.h>
@@ -193,10 +193,10 @@ Value Interpreter::execute_statement(GlobalObject& global_object, const Statemen
     return last_value;
 }
 
-DeclarativeEnvironmentRecord* Interpreter::current_declarative_environment_record()
+FunctionEnvironmentRecord* Interpreter::current_function_environment_record()
 {
-    VERIFY(is<DeclarativeEnvironmentRecord>(vm().call_frame().environment_record));
-    return static_cast<DeclarativeEnvironmentRecord*>(vm().call_frame().environment_record);
+    VERIFY(is<FunctionEnvironmentRecord>(vm().call_frame().environment_record));
+    return static_cast<FunctionEnvironmentRecord*>(vm().call_frame().environment_record);
 }
 
 }