[llvm-branch-commits] [BOLT] Emit empty FDE for injected functions (PR #87967)

[Amir Ayupov via llvm-branch-commits]

https://github.com/aaupov created https://github.com/llvm/llvm-project/pull/87967

This fixes an issue where `PatchEntries` overwrites function body but
keeps CFI untouched. Existing FDEs thus become invalid. This doesn't
affect unwinding because patched functions are transparent from
EH/unwinding perspective, but it breaks BOLT during disassembling those
functions.

Test Plan: TBD