Undefined symbol on test 21

[gabrielrodcanal]

Hi there,
I'm trying to build test 21 https://github.com/Xilinx/mlir-air/tree/main/test/airhost/21_air_nd_memcpy_2d, but I'm getting an undefined symbol error when linking:

ld.lld: error: undefined symbol: air::segments::segment_0::mlir_aie_write_buffer_scratch_0_0(aie_libxaie_ctx_t*, int, int)
>>> referenced by test.cpp:106 (/home/nx08/nx08/s2081362-2/mlir-air/test/airhost/21_air_nd_memcpy_2d/test.cpp:106)

Has anyone else encountered this issue?

[gabrielrodcanal]

Fix in PR #458. Other tests suffer from the same issue and would benefit from a Makefile. Happy to contribute those to the repository if the maintainers are happy with these changes.