[libc++abi] Don't try calling __libcpp_aligned_free when aligned allocation is disabled

See https://reviews.llvm.org/rGa78aaa1ad512#962077 for details.

libcxxabi/src/fallback_malloc.cpp

@@ -234,7 +234,11 @@ void __aligned_free_with_fallback(void* ptr) {
   if (is_fallback_ptr(ptr))
     fallback_free(ptr);
   else {
+#if defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION)
+    ::free(ptr);
+#else
     std::__libcpp_aligned_free(ptr);
+#endif
   }
 }