[llvm] [TableGen] Rework error reporting for duplicate Feature/Processor. (PR #102257)

[via llvm-commits]

zeroomega wrote:

> aarch64-adrp-ldr-got.s

It is not related to this patch and it failed entirely due to coincidence. The test try to match:

 ```
# ADR:        nop
# ADR-NEXT:   adr    x1
```

The build path is randomized: `/var/lib/buildbot/fuchsia-x86_64-linux/build/llvm-build-nopw1ndl` which contains `nop` so it got matched. But `adr x1` is not in the next line. That's why it throws an error. Maybe we should modify the build script to avoid using randomized directory, instead, just use fixed one, and delete it when we do a fresh build. FYI @petrhosek 



https://github.com/llvm/llvm-project/pull/102257