[llvm] [X86][utils] Support `-basic-block-sections` in `update_llc_test_checks` (PR #178999)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Precommitting a test for the exact issue this patch is trying to solve isn't exactly proper motivation. All of the basic block sections tests seem to be doing fine currently without being autogenerated by `update_llc_test_checks`, unless I'm missing something.

https://github.com/llvm/llvm-project/pull/178999