[HIP] add test for uses of std::array on device code

[jmmartinez]

First attempt at testing llvm/llvm-project#136133 .

Draft for the moment, I have to manually test this further.

[yxsamliu]

can std::array be parameter type of kernel or device functions?

can it be used as non-constexpr stack variable in kernel or device functions?

if so, can we have testcases for those?

[jmmartinez]

can std::array be parameter type of kernel or device functions?

It can be used as a parameter for device and kernel functions (which would trigger the copy-constructor). According to the c++ reference std::array is an aggregate in the the same way as a struct with an array inside; so the same rules should apply. For example, all the constructors are implicitly declared.

I'm not sure that adding the copy-constructor case here will improve the coverage of the test (we're testing the interaction with the standard C++ library, and there is no code to test since these behaviors are implicitly defined by clang). Passing an aggregate as an argument should be covered by the tests on clang's side.

I can add the test for std::array constructors here too if you think we really need them.

can it be used as non-constexpr stack variable in kernel or device functions?

This is already covered in the test. We check std::array both in a constexpr and non-constexpr context.

[jmmartinez]

I've moved the array test from CUDA to HIP since I have less control over CUDA buildbots. The hipify tests are already merged.

[jmmartinez]

Would you be ok to:

1. land this change and see how the build-bots behave.
2. then land [CUDA][HIP] Add a __device__ version of std::__glibcxx_assert_fail() llvm-project#136133

[Artem-B]

The commit appears to break CUDA tests:
https://lab.llvm.org/buildbot/#/builders/69/builds/22366 (see the "Configuring CUDA test-suite" section logs)

CMake Error at cmake/modules/TestSuite.cmake:48 (add_executable):
  No SOURCES given to target: array-cuda-12.4-c++20-libstdc++-9
Call Stack (most recent call first):
  cmake/modules/TestSuite.cmake:79 (llvm_test_executable_no_test)
  cmake/modules/GPUTestVariant.cmake:48 (llvm_test_executable)
  cmake/modules/GPUTestVariant.cmake:71 (create_one_local_test_f)
  External/CUDA/CMakeLists.txt:77 (create_one_local_test)
  External/CUDA/CMakeLists.txt:170 (create_local_cuda_tests)
  External/CUDA/CMakeLists.txt:347 (create_cuda_test_variant)
  External/CUDA/CMakeLists.txt:376 (create_cuda_tests)

[Artem-B]

There's no matching array.cu file committed under CUDA which makes cmake configuration fail.