Rename PetscValidPointer -> PetscAssertPointer

Lint apply: mat

Merge branch 'barry/2023-06-15/add-fortran-file-viewer' into 'main'

Allow one to attach a PETSCVIEWERASCII to a Fortran file unit

See merge request petsc/petsc!6607

HAVE_FORTRAN should be USE_FORTRAN_BINDINGS since it is about generating the Fortran bindings, not about if the Fortran compiler exists

Optimize MatGetDiagonal_MPIDense()

Collapse MatDense_CUPM::Shift() and MatDense_CUPM::GetDiagonal() down to base class

Add MatGetDiagonal_CUPM

docs: additional chapter_ -> ch_ change in main after merge of release changes from !6520

Merge remote-tracking branch 'origin/release'

remove ifdef __cplusplus from C++-only headers

Don't use PetscMemcpy() or PetscArraycpy() to copy the ops struct

change to consistent use of ch_xxx for chapter names in the docs, instead of a mix of ch_xx and chapter_xx

Merge branch 'stefanozampini/h2opus-dmdakokkos' into 'main'

Add support for KOKKOS in H2OPUS

See merge request petsc/petsc!6408

Add MatCreateDenseForVecType

Remove old implementation (only in main) and update test

and a convenience internal routine to allocate the column vector when requested

Add MatDenseCUPMSetPreallocation

Minor