LibJS/Bytecode: Move CreateVariable impl to CommonImplementations

Userland/Libraries/LibJS/Bytecode/CommonImplementations.cpp

@@ -423,4 +423,30 @@ MarkedVector<Value> argument_list_evaluation(Bytecode::Interpreter& interpreter)
     return argument_values;
 }
 
+ThrowCompletionOr<void> create_variable(VM& vm, DeprecatedFlyString const& name, Op::EnvironmentMode mode, bool is_global, bool is_immutable, bool is_strict)
+{
+    if (mode == Op::EnvironmentMode::Lexical) {
+        VERIFY(!is_global);
+
+        // Note: This is papering over an issue where "FunctionDeclarationInstantiation" creates these bindings for us.
+        //       Instead of crashing in there, we'll just raise an exception here.
+        if (TRY(vm.lexical_environment()->has_binding(name)))
+            return vm.throw_completion<InternalError>(TRY_OR_THROW_OOM(vm, String::formatted("Lexical environment already has binding '{}'", name)));
+
+        if (is_immutable)
+            return vm.lexical_environment()->create_immutable_binding(vm, name, is_strict);
+        return vm.lexical_environment()->create_mutable_binding(vm, name, is_strict);
+    }
+
+    if (!is_global) {
+        if (is_immutable)
+            return vm.variable_environment()->create_immutable_binding(vm, name, is_strict);
+        return vm.variable_environment()->create_mutable_binding(vm, name, is_strict);
+    }
+
+    // NOTE: CreateVariable with m_is_global set to true is expected to only be used in GlobalDeclarationInstantiation currently, which only uses "false" for "can_be_deleted".
+    //       The only area that sets "can_be_deleted" to true is EvalDeclarationInstantiation, which is currently fully implemented in C++ and not in Bytecode.
+    return verify_cast<GlobalEnvironment>(vm.variable_environment())->create_global_var_binding(name, false);
+}
+
 }

Userland/Libraries/LibJS/Bytecode/CommonImplementations.h

@@ -32,5 +32,6 @@ struct CalleeAndThis {
 ThrowCompletionOr<CalleeAndThis> get_callee_and_this_from_environment(Bytecode::Interpreter&, DeprecatedFlyString const& name, u32 cache_index);
 Value new_regexp(VM&, ParsedRegex const&, DeprecatedString const& pattern, DeprecatedString const& flags);
 MarkedVector<Value> argument_list_evaluation(Bytecode::Interpreter&);
+ThrowCompletionOr<void> create_variable(VM&, DeprecatedFlyString const& name, Op::EnvironmentMode, bool is_global, bool is_immutable, bool is_strict);
 
 }

Userland/Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -819,34 +819,8 @@ ThrowCompletionOr<void> EnterObjectEnvironment::execute_impl(Bytecode::Interpret
 
 ThrowCompletionOr<void> CreateVariable::execute_impl(Bytecode::Interpreter& interpreter) const
 {
-    auto& vm = interpreter.vm();
     auto const& name = interpreter.current_executable().get_identifier(m_identifier);
-
+    return create_variable(interpreter.vm(), name, m_mode, m_is_global, m_is_immutable, m_is_strict);
-    if (m_mode == EnvironmentMode::Lexical) {
-        VERIFY(!m_is_global);
-
-        // Note: This is papering over an issue where "FunctionDeclarationInstantiation" creates these bindings for us.
-        //       Instead of crashing in there, we'll just raise an exception here.
-        if (TRY(vm.lexical_environment()->has_binding(name)))
-            return vm.throw_completion<InternalError>(TRY_OR_THROW_OOM(vm, String::formatted("Lexical environment already has binding '{}'", name)));
-
-        if (m_is_immutable)
-            return vm.lexical_environment()->create_immutable_binding(vm, name, m_is_strict);
-        else
-            return vm.lexical_environment()->create_mutable_binding(vm, name, m_is_strict);
-    } else {
-        if (!m_is_global) {
-            if (m_is_immutable)
-                return vm.variable_environment()->create_immutable_binding(vm, name, m_is_strict);
-            else
-                return vm.variable_environment()->create_mutable_binding(vm, name, m_is_strict);
-        } else {
-            // NOTE: CreateVariable with m_is_global set to true is expected to only be used in GlobalDeclarationInstantiation currently, which only uses "false" for "can_be_deleted".
-            //       The only area that sets "can_be_deleted" to true is EvalDeclarationInstantiation, which is currently fully implemented in C++ and not in Bytecode.
-            return verify_cast<GlobalEnvironment>(vm.variable_environment())->create_global_var_binding(name, false);
-        }
-    }
-    return {};
 }
 
 ThrowCompletionOr<void> SetVariable::execute_impl(Bytecode::Interpreter& interpreter) const