[llvm] [workflows] Use -g instead of -g1 for the abi tests (PR #133968)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

LGTM, though I wonder whether it might make sense to just switch to the RelWithDebugInfo configuration now, instead of manually specifying CFLAGS? That would use -O2 instead of -Og, but I don't think that should really matter for the purposes of ABI comparison.

https://github.com/llvm/llvm-project/pull/133968