Implement the changes in all language modes.
LWG3506 "Missing allocator-extended constructors for priority_queue"
makes the following changes:
- New allocator-extended constructors for priority_queue.
- New deduction guides targeting those constructors.
LWG3522: "Missing requirement on InputIterator template parameter
for priority_queue constructors". The iterator parameter should be
constrained to actually be an iterator type. `priority_queue{1,2}`
should be SFINAE-friendly ill-formed.
Also, do a drive-by fix in the allocator-extended move constructor:
there's no need to do a `make_heap` after moving from `__q.c` into
our own `c`, because that container was already heapified when it
was part of `__q`. [priqueue.cons.alloc] actually specifies the
behavior and does *not* mention calling `make_heap`. I think this
was just a copy-paste thinko. It dates back to the initial import
of libc++.
Differential Revision: https://reviews.llvm.org/D106824
Differential Revision: https://reviews.llvm.org/D106827
Updates the status pages with the LWG issues accepted in the Standard
during the June 2021 plenary session. The LWG papers for this meeting
have been added in D105103.
Differential Revision: https://reviews.llvm.org/D106529
Arthur O'Dwyer