un-nest some logic

spec.html

@@ -13455,13 +13455,12 @@ <h1>
         1. Let _constructorEnv_ be the LexicalEnvironment of _calleeContext_.
         1. Let _result_ be Completion(OrdinaryCallEvaluateBody(_F_, _argumentsList_)).
         1. Remove _calleeContext_ from the execution context stack and restore _callerContext_ as the running execution context.
-        1. If _result_ is a return completion, then
-          1. If _result_.[[Value]] is an Object, return _result_.[[Value]].
-          1. If _kind_ is ~base~, return _thisArgument_.
-          1. If _result_.[[Value]] is not *undefined*, throw a *TypeError* exception.
-        1. Else,
-          1. Assert: _result_ is a throw completion.
+        1. If _result_ is a throw completion, then
           1. Return ? _result_.
+        1. Assert: _result_ is a return completion.
+        1. If _result_.[[Value]] is an Object, return _result_.[[Value]].
+        1. If _kind_ is ~base~, return _thisArgument_.
+        1. If _result_.[[Value]] is not *undefined*, throw a *TypeError* exception.
         1. Let _thisBinding_ be ? _constructorEnv_.GetThisBinding().
         1. Assert: _thisBinding_ is an Object.
         1. Return _thisBinding_.