[libcxx-commits] [libcxx] [libc++][test] Move the SFINAE test for return types of `quoted` to `libcxx/test/libcxx/` (PR #157026)

[Louis Dionne via libcxx-commits]

================
@@ -16,6 +16,8 @@
 //   with the wrong CharTraits. To avoid our having to create working
 //   ostreams with weird CharTraits, this is a compile-only test.
 
+//   It is unspecified whether these operators are SFINAE-friendly. We choose to make them so.
----------------
ldionne wrote:

```suggestion
//   It is unspecified whether these operators are SFINAE-friendly. We choose to make them so.
//   See https://wg21.link/LWG4364 for whether this should be considered an extension or not.
```

https://github.com/llvm/llvm-project/pull/157026