libstdc++: Fix various bugs in ranges_algo.h [PR100187, ...]

libstdc++: Fix various bugs in ranges_algo.h [PR100187, ...]

This fixes some bugs with our ranges algorithms in uncommon situations,
such as when the return type of a predicate is a non-copyable class type
that's implicitly convertible to bool (PR100187), when a comparison
predicate isn't invocable as an rvalue (PR100237), and when the return
type of a projection function is non-copyable (PR100249).

This also fixes PR100287, which reports that we're moving __first twice
when constructing with it an empty subrange in ranges::partition.

libstdc++-v3/ChangeLog:

	PR libstdc++/100187
	PR libstdc++/100237
	PR libstdc++/100249
	PR libstdc++/100287
	* include/bits/ranges_algo.h (__search_n_fn::operator()): Give
	the __value_comp lambda an explicit bool return type.
	(__is_permutation_fn::operator()): Give the __proj_scan local
	variable auto&& return type.  Give the __comp_scan lambda an
	explicit bool return type.
	(__remove_fn::operator()): Give the __pred lambda an explicit
	bool return type.
	(__partition_fn::operator()): Don't std::move __first twice
	when returning an empty subrange.
	(__min_fn::operator()): Don't std::move __comp.
	(__max_fn::operator()): Likewise.
	(__minmax_fn::operator()): Likewise.