Guard the concepts-based iterator tag dispatch in parallel_for_each on

__TBB_CPP20_CONCEPTS_PRESENT rather than __TBB_CPP20_PRESENT. The latter only

tests the language mode (__TBB_LANG >= 202002L), so toolchains that accept

-std=c++20 but ship a pre-C++20 standard library -- e.g. Apple clang 14 with

the macOS 11.3 SDK, as used on CRAN's macOS x86_64 builders -- would take the

concepts branch and fail with 'no member named random_access_iterator in

namespace std'.

This is the upstream fix from oneTBB PR #1611 (issue #1552), first released in

oneTBB 2022.1.0; it can be dropped once the bundled oneTBB is updated past

2022.0.0.

diff --git a/src/tbb/include/oneapi/tbb/parallel_for_each.h b/src/tbb/include/oneapi/tbb/parallel_for_each.h

index ce68a7ff..13d945ce 100644

--- a/src/tbb/include/oneapi/tbb/parallel_for_each.h

+++ b/src/tbb/include/oneapi/tbb/parallel_for_each.h

@@ -409,7 +409,7 @@ public:

template<typename It>

using tag = typename std::iterator_traits<It>::iterator_category;

-#if __TBB_CPP20_PRESENT

+#if __TBB_CPP20_CONCEPTS_PRESENT

template <typename It>

struct move_iterator_dispatch_helper {

using type = It;

@@ -448,7 +448,7 @@ using iterator_tag_dispatch = typename

std::input_iterator_tag

>::type

>::type;

-#endif // __TBB_CPP20_PRESENT

+#endif // __TBB_CPP20_CONCEPTS_PRESENT

template <typename Body, typename Iterator, typename Item>

using feeder_is_required = tbb::detail::void_t<decltype(tbb::detail::invoke(std::declval<const Body>(),