Merge PR #32415 into master

* refs/pull/32415/head:
	include/cpp-btree: use inline variable to define btree_is_key_compare_to
	include/cpp-btree: use std::conditional_t<>
	include/cpp-btree: use static_assert()
	include/interval_set: use interval_set when appropriate
	include/interval_set: rename some types
	include/cpp-btree: add emplace_hint()

Reviewed-by: Sage Weil <sage@redhat.com>