QString: add missing char8_t* constructor / fromUtf8 overloads

Currently we support:

  QString s = QString::fromUtf(u8"foo", 3);

But we don't support

  QString s = QString::fromUtf8(u8"foo");
  QString s(u8"foo");

There's no reason not to have these two functions. Guess what,
we've actually got code _in Qt_ that tries to build a QString out of
a char8_t; that code stops compiling under C++20 (which is supported,
but not CI-tested at the moment, it seems).

Re-add the missing constructor and fromUtf8 overloads.

[ChangeLog][QtCore][QString] Added a constructor and a fromUtf8()
overload taking a `const char8_t *` argument.

Task-number: QTQAINFRA-4117
Task-number: QTQAINFRA-4242
Change-Id: I1f0ae658b3490b9e092941cabcc7fb8fc4c51aa3
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
(cherry picked from commit b322bfcc14845a4b6a6eef85ef359b1e4591a5ca)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

0 files changed, 0 insertions, 0 deletions