[Decomp] Math library: transform and quaternion (#344)

* decompile transform

* types for quaternion

* part of quaternion

* finish quaternion

* fix offline test reference

* wip fix to let issue

* fix

decompiler/IR2/FormStack.cpp

@@ -344,6 +344,10 @@ std::vector<FormElement*> FormStack::rewrite(FormPool& pool, const Env& env) {
       result.push_back(e.elt);
     }
   }
+
+  if (result.empty()) {
+    result.push_back(pool.alloc_element<EmptyElement>());
+  }
   return result;
 }