LibWeb+LibJS: Skip function environment allocation if possible

If a function has the following properties:
- uses only local variables and registers
- does not use `this`
- does not use `new.target`
- does not use `super`
- does not use direct eval() calls

then it is possible to entirely skip function environment allocation
because it will never be used

This change adds gathering of information whether a function needs to
access `this` from environment and updates `prepare_for_ordinary_call()`
to skip allocation when possible.

For now, this optimisation is too aggressively blocked; e.g. if `this`
is used in a function scope, then all functions in outer scopes have to
allocate an environment. It could be improved in the future, although
this implementation already allows skipping >80% of environment
allocations on Discord, GitHub and Twitter.

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -972,7 +972,7 @@ ThrowCompletionOr<void> eval_declaration_instantiation(VM& vm, Program const& pr
     for (auto& declaration : functions_to_initialize.in_reverse()) {
         // a. Let fn be the sole element of the BoundNames of f.
         // b. Let fo be InstantiateFunctionObject of f with arguments lexEnv and privateEnv.
-        auto function = ECMAScriptFunctionObject::create(realm, declaration.name(), declaration.source_text(), declaration.body(), declaration.parameters(), declaration.function_length(), declaration.local_variables_names(), lexical_environment, private_environment, declaration.kind(), declaration.is_strict_mode(), declaration.might_need_arguments_object());
+        auto function = ECMAScriptFunctionObject::create(realm, declaration.name(), declaration.source_text(), declaration.body(), declaration.parameters(), declaration.function_length(), declaration.local_variables_names(), lexical_environment, private_environment, declaration.kind(), declaration.is_strict_mode(), declaration.uses_this(), declaration.might_need_arguments_object());
 
         // c. If varEnv is a global Environment Record, then
         if (global_var_environment) {