[LLVM] Codegen visitor for printing generating benchmarking kernels

[pramodk]

• [ ] Generating kernel with ./bin/nmodl hh.mod llvm --ir but still InstanceStruct generation and overall cleaning missing here.

[bbpbuildbot]

Logfiles from GitLab pipeline #60534 (:no_entry:) have been uploaded here!

Status and direct links:

• :white_check_mark: spack_setup
• :no_entry: build:intel
• :no_entry: build_cuda:gcc
• :fast_forward: test:intel
• :fast_forward: test_benchmark:gcc