Minor fixes

Add static to internal functions

Profiling: Improve !defined(PETSC_USE_LOG) #defines

- If we cast macro arguments to void, we can avoid unused errors that have
forced lots of conditionally included code like this:

```c
#if def

Profiling: Improve !defined(PETSC_USE_LOG) #defines

- If we cast macro arguments to void, we can avoid unused errors that have
forced lots of conditionally included code like this:

```c
#if defined(PETSC_USE_LOG)
PetscLogEvent event;
#endif
```

- Having global counters like petsc_TotalFlops externed event
if !PetscDefined(USE_LOG) helps to remove a lot of needless
`#ifdef`s around code that can instead be placed in
`if (PetscDefined(USE_LOG)) {}` blocks.

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Rename PetscValidPointer -> PetscAssertPointer

Deploy new PetscValidPointer, remove PetscValidXXXPointer

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

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

Add MatGetDiagonal_CUPM

Merge remote-tracking branch 'origin/release'