Merge branch 'libbpf: usdt arm arg parsing support'

Puranjay Mohan says:

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This series add the support of the ARM architecture to libbpf USDT. This
involves implementing the parse_usdt_arg() function for ARM.

It was seen that the last part of parse_usdt_arg() is repeated for all architectures,
so, the first patch in this series refactors these functions and moved the post
processing to parse_usdt_spec()

Changes in V2[1] to V3:

- Use a tabular approach to find register offsets.
- Add the patch for refactoring parse_usdt_arg()
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Signed-off-by: Andrii Nakryiko <andrii@kernel.org>