Exclude MSVC up to 19.16 from using std::launder

[franzpoeschel]

Description

This PR fixes/works around an internal compiler error triggered by MSVC 19.16 in our CI when trying to upgrade to pybind11 v3.0.1:

_deps\fetchedpybind11-src\include\pybind11\pybind11.h(3008): fatal error C1001: An internal error has occurred in the compiler. [C:\projects\openpmd-api\build\openPMD.py.vcxproj]
  (compiler file 'd:\agent\_work\8\s\src\vctools\compiler\utc\src\p2\main.c', line 187)
   To work around this problem, try simplifying or changing the program near the locations listed above.
  Please choose the Technical Support command on the Visual C++
   Help menu, or open the Technical Support help file for more information

With git-bisect, I found this commit as the first failing commit. More precisely, the compiler crash is caused by this single line:

pybind11/include/pybind11/pybind11.h

Line 364 in 57b9a0a

new (capture::from_data(rec->data)) capture{std::forward<Func>(f)};

This PR now raises the minimum MSVC version with support for std::launder to 19.20, thus excluding also 19.14, 19.15 and 19.16. This locally fixes the error for me.

Suggested changelog entry:

Block MSVC up to 19.16 from use of std::launder due to internal compiler errors

Other

This PR is for the master branch, upon which I cannot test its effect since our project does not seem to compile against the current master branch: _deps/fetchedpybind11-src/include/pybind11/pybind11.h:2462:25: error: static assertion failed: def_property family does not currently support keep_alive. Use a py::cpp_function instead..
Should I additionally submit a PR for v3.0?

[rwgk]

I think that should be fine, but could you please add // See PR #5968 to the end of the line? If std::launder causes trouble again, that'll make it much easier for others to discover this PR and to get the full context.

[rwgk]

I think that should be fine, but could you please add // See PR #5968 to the end of the line? If std::launder causes trouble again, that'll make it much easier for others to discover this PR and to get the full context.

I just had a minute to quickly do this. I'll merge when I see that the CI is done.

[franzpoeschel]

Thank you!

[franzpoeschel]

Should I additionally submit a PR for the v3.0 branch for an eventual 3.0.2 release?

[rwgk]

Should I additionally submit a PR for the v3.0 branch for an eventual 3.0.2 release?

No need, thanks. We'll just merge the current master into the v3.0 branch.