[llvm] [PPC] Don't emit overflow error on branches accross different sections. (PR #206812)

[Nikita Popov via llvm-commits]

nikic wrote:

> If a branch is to a symbol in a different sections we have to give the linker a chance to fixup the overflow. On AIX in particualr we have to emit the masked off overflowed value into the bits to be relocated as the linker uses them in its final relocation calculation for calls.

Could you please provide some more details here? What kind of fixup is this about, what relocation gets emitted, what is the meaning of the fixup value for this relocation, and why is it legal for the value to be truncated?

https://github.com/llvm/llvm-project/pull/206812