Merged with P1721R2, which also converted the Remarks: element to a
Constraints: element, but with a more consistent wording pattern.

…metic from pointer-interconvertible object

…ot satisfied in the example

…ime<Duration2, TimeZonePtr2>

[time.zone.zonedtime.ctor] Inserted "the type" before the non-functions
in the constraints because otherwise the wording
"the return type of f(A) and B" can be parsed in a way that makes no sense.

…ides

…at negative numbers

[iterator.concept.winc] Fix "Expressions" to be singular when refering to "E".

…ally mean what we say" wording

…load constexpr

[range.refinements] Removed redundant parens and added missing "is true".

…th seconds

…ble iterators

… irange<const V>

…tor for a move-only iterator

Also fixes NB US 152 (C++20 CD).

… 169)

Also fixes NB DE 169 (C++20 CD).

…tor_category