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

[Rainer Orth via llvm-commits]

rorth wrote:

> LGTM. Let's see if this fixes the bots.

Please don't commit this as is: this will not only **not** fix the affected bots, it will break all others.  I've since verified that the current version of the patch `FAIL`s on `x86_64-pc-linux-gnu` in the same ways as on Solaris: the test is syntactically wrong!

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