Fix compiler warning due to partially overridden CompressedSparseMatrix::permute

[sebastiangrimberg]

This problem probably popped up only recently since this file is now being installed correctly is my guess.

[pghysels]

Thank you. Indeed some headers were not installed correctly.
I just fixed warning I noticed when compiling with clang, or hipcc: 19d22f7
But I'm not seeing this warning you mention for the permute routine. What compiler are you using?
Perhaps I could also just remove the virtual keyword for the permute routine taking 2 vectors?

[sebastiangrimberg]

Thanks for addressing these! These warnings appear when building a file which includes StrumpackSparseSolverMPIDist.hpp with nvcc using -Wall -pedantic. I don't get the warnings when building STRUMPACK likely because the CUDA compilers are only used where necessary. MFEM uses the CUDA compilers everywhere which leads to the issue with nvcc.

[pghysels]

I see lot's of warnings now when compiling with the NVHPC compilers on Perlmutter.
I will try to fix all these.

[pghysels]

I fixed a lot of warnings.
I sometimes still see unused variable warnings, for things that are only used in OpenMP pragmas. I'll fix those later.

[sebastiangrimberg]

Awesome! Looks great thanks, I'll close this PR.