Fix missing "Key" and incorrect "Command" for manual page listing of Options Database Key(s):

Commit-type: documentation
/spend 10m

Cherry-pick init fix from 1015a2a477dd2695c1e05348307aec5fc5bfe5fb

Add C++ implementation of khash map as a drop-in replacement for std::unordered_map

Make PointerAttributes default constructable again

Merge remote-tracking branch 'origin/release'

Merge branch 'jacobf/2022-11-09/fix-issue-1279' into 'release'

Fix Wrong type assignment in PetscDeviceContextSetFromOptions

See merge request petsc/petsc!5818

Implement workaround for clang and gcc bug for nested class default initializers

Fix #1279: Don't assume MPI_COMM_SELF/MPI_COMM_WORLD are MPI_Comm's, some MPI implementations define these as enums instead

Add explicit test for PetscDevice command line init sequence controls

Merge remote-tracking branch 'origin/release'

A few more codespell fixes

Merge remote-tracking branch 'origin/release'

Docs: remove or add space before back tick

Use PetscTryTypeMethod() in dctontext.cxx, and set the device before we call createcontext

Add explicit tests for the marked object map

Fixup misc C++ code so MSVC does not balk at it

Add a fast-path when repeatedly marking the same object with conflicting access modes to avoid excessive event churn

source code format changes due to .clang-format changes