[llvm] [BOLT] Enhance fixed indirect branch handling (PR #71324)

[Vladislav Khmelevsky via llvm-commits]

yota9 wrote:

@maksfb  Answering your question - I saw a few functions here during fixing the #70771 . As I wrote to Amir #71278 it looks like O0 file linked in with the code like:
adr x0, 1f
br x0
1: ret

So last br might be omitted at least. Plus I've found out that the adr on function makes it non-simple due to "potentially escaped address" in handleAddressRef, so I'm thinking to allow it for handling such situations.

https://github.com/llvm/llvm-project/pull/71324