[llvm] [test] Fix `coro-split-dbg-labels.ll` for non-x86 (PR #147087)

[Alex Bradbury via llvm-commits]

asb wrote:

FYI this has broken the RISC-V bots as well. If a fix to the test isn't obvious, I think temporarily removing this test to get the bots green is sensible.

LIke a number of the other tests in llvm/tests/Transforms/Coroutines have, I suspect that the simplest solution is to add the x86 target-triple and datalayout to the input file. We should really have `REQUIRES: x86-registered-target` as well, but it seems tests in this directory are bad at providing it (and all of the bots are building the X86 target I assume).

https://github.com/llvm/llvm-project/pull/147087