[libcxx-commits] [libcxx] [libc++][ranges] Fix the LWG 3568 test for `basic_istream_view` (PR #215589)

[A. Jiang via libcxx-commits]

https://github.com/frederick-vs-ja approved this pull request.

I reworded the PR description to avoid tagging anybody and explained the modifications to the existing test case. Please double-check the changes.

We generally use the PR title and description as the squashed commit message by default. It will be disturbing if the squashed commit contains tagging and is replicated in some forks in GitHub since GitHub will send mail(s) when the replicated commit is pushed.

https://github.com/llvm/llvm-project/pull/215589