P3179R9 Parallel Range Algorithms

[StephanTLavavej]

WG21-P3179R9 Parallel Range Algorithms
WG21-P3709R2 Reconsider Parallel ranges::rotate_copy And ranges::reverse_copy
WG21-P3923R0 Additional NB Comment Resolutions For Kona 2025 (section 2.6)
LWG-4297 Missing permutable constraint for iterator overloads in Parallel Range Algorithms
LWG-4431 Parallel std::ranges::destroy should allow exceptions
LWG-4441 ranges::rotate do not handle sized-but-not-sized-sentinel ranges correctly

Wording clarifications:
LWG-4463 Change wording to 'model' from 'subsumes' in [algorithms.parallel.user]
LWG-4464 [alg.merge] Wording tweaks
LWG-4465 [alg.partitions] Clarify Returns: element

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INCREASED feature-test macro (expected):

#define __cpp_lib_parallel_algorithm 202506L

Note: We're focused on implementing the remaining library-only features in C++23. Until that's done, we will NOT be accepting PRs for C++26 features.