Add arm-native build and test on Ubuntu

[myungjoo]

We can run arm natively with github-action.
Test fp16 natively on arm machines!

[skykongkong8]

Great to test them automatically on action!

[skykongkong8]

if get_option('enable-fp16') 
  if arch == 'arm'
    error ('FP16/ARM code (blas_neon.cpp) uses armv8.2 instructions. armv7 is not supported.')
  elif arch == 'aarch64' or get_option('platform') == 'android'
    if get_option('enable-neon')
      tensor_sources += 'blas_neon.cpp'
      tensor_headers += 'blas_neon.h'
      subdir('hgemm')
      nntrainer_inc += include_directories('hgemm')
      nntrainer_inc_abs += meson.current_source_dir() / 'hgemm'

      subdir('matrix_transpose_neon')
      nntrainer_inc += include_directories('matrix_transpose_neon')
      nntrainer_inc_abs += meson.current_source_dir() / 'matrix_transpose_neon'
    endif
  endif
endif

matrix_transpose_neon is included like above. Is ubuntu-22.04-arm armv7?
If it is, it should not built with enable-fp16=true

+) I found additional bug. #2832 is merged recently, and I missed to divide fp32 / fp16 matrix transpose with neon. I will fix this accordingly asap -> fixed on #2898

[myungjoo]

It's aarch64.

[skykongkong8]

I have a quick question!
It seems meson libdir at ubuntu_clean_meson_build.yml is being set like below :

--libdir=lib/x86_64-linux-gnu \

would this work with ubuntu-22.04-arm as well?

[EunjuYang]

It looks great! LGTM!

[myungjoo]

I have a quick question! It seems meson libdir at ubuntu_clean_meson_build.yml is being set like below :

--libdir=lib/x86_64-linux-gnu \

would this work with ubuntu-22.04-arm as well?

Nope. that should be fixed. Hardcoding libdir is not a good idea.

[myungjoo]

@skykongkong8 libdir is fixed. Let's not specify if not needed.

[djeong20]

LGTM