[llvm] [Object] Extract format-agnostic BBAddrMap decoder (PR #188435)

[Haohai Wen via llvm-commits]

HaohaiWen wrote:

What actually changed:
  1. Error messages — "SHT_LLVM_BB_ADDR_MAP" → "BB address map" in 4 places (version error + 3 feature-version errors)
  2. Removed describe(EF, Sec) from the zero BB ranges error — the shared decoder has no ELF section context
  3. ExtractAddress simplified — no longer checks IsRelocatable / asserts / unwraps error internally; delegates to the ResolveAddress callback directly

https://github.com/llvm/llvm-project/pull/188435