[llvm] [BOLT] Fix LLVM_APPEND_VC_REV support (PR #142410)

[Amir Ayupov via llvm-commits]

aaupov wrote:

We're supposed to set this flag on NFC builder:
https://github.com/llvm/llvm-zorg/blob/e7c3dc5f8ead5ba5ea8dd819dee243d87f65b375/buildbot/osuosl/master/config/builders.py#L2949

At a time of enabling, I verified that if the changes are not affecting BOLT, it's not rebuilt (which ensures that NFC checks are not triggered). Perhaps it was broken at some point, causing changes in the bolt binary.

https://github.com/llvm/llvm-project/pull/142410