Change global tag variables to local variables.

[seyonglee]

This PR changes global tag variables accessed in Kokkos subview-related functions to local variables, so that NVHPC OpenACC compiler (nvc++ version higher than 24.5) can compile a Kokkos program where a subview is created in a device kernel.
This PR contains the same changes as mdspan code changes in Kokkos PR 9486 (kokkos/kokkos#9486)

[nmm0]

Do you know why this is causing problems? Is it an nvc++ compiler bug?

[seyonglee]

Do you know why this is causing problems? Is it an nvc++ compiler bug?

If a subview is created in a device kernel (e.g., in a Kokkos parallel_for()), several global tag symbols are accessed, which cannot be correctly captured by nvc++ compiler if version > 24.5.

[nmm0]

Fascinating, even if they are constexpr? Well either way I think this is fine

[dalg24]

Just noting that mdspan_non_standard would now become unused.

cc @mhoemmen @weinbe2

[mhoemmen]

Thanks for the fix! : - )

@seyonglee wrote:

... so that NVHPC OpenACC compiler (nvc++ version higher than 24.5) can compile a Kokkos program where a subview is created in a device kernel.

Does this mean "is able to build without errors" or "is able to build and pass tests"?

[seyonglee]

Thanks for the fix! : - )

@seyonglee wrote:

... so that NVHPC OpenACC compiler (nvc++ version higher than 24.5) can compile a Kokkos program where a subview is created in a device kernel.

Does this mean "is able to build without errors" or "is able to build and pass tests"?

With this update, the following two Kokkos unit tests, which create subview in a device kernel, can be built without errors and pass tests:

core/unit_test/range_policy/TestRangePolicyExecutionTypes.hpp
core/unit_test/TestSubView_c13.hpp