QDebug: fix std::string/view stream operators; add u8 versions

Make them templates, for two reasons:

- so they can accept std::pmr types and, in general, any basic_string
  with custom allocators and char_traits

- to break overload ambiguities with the Qt string view types

Also, add the missing C++20 char8_t overloads.

Also, avoid creation of a QString in the sizeof(wchar_t) == 2 case
(Windows). Add a comment to optimize for the sizeof(wchar_t) != 2 case
later.

Found in API review.

Pick-to: 6.5
Change-Id: I30139520f582a38863a0936f8eca4b1ed33e37c8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

0 files changed, 0 insertions, 0 deletions