[PATCH] libstdc++: Also disable caching of reverse_view::begin() for common_ranges

[Jonathan Wakely]

On 28/02/20 11:34 -0500, Patrick Palka wrote:
>When the underlying range models common_range, then reverse_view::begin() is
>O(1) without caching.  So we should disable the cache in this case too.
>
>libstdc++-v3/ChangeLog:
>
>	* include/std/ranges (reverse_view::_S_needs_cached_begin): Set to false
>	whenever the underlying range models common_range.

OK, thanks.