[llvm] [AMDGPU][RFC] Combine asm and disasm tests. (PR #90214)

[Ivan Kosarev via llvm-commits]

kosarev wrote:

> Utilize `-SAME:` directives?
> 
> ```
> # RUN: llvm-mc ... %s | FileCheck
> # RUN: llvm-mc -filetype=obj ... %s | llvm-objdump -d - | FileCheck --check-prefixes=CHECK,ENCODING
> 
> # CHECK: nop
> # ENCODING-SAME: [0,0,0,0]
> nop
> ```

Again, this wouldn't work because `llvm-objdump -d` does not print encodings in the `[0,0,0,0]` form.

https://github.com/llvm/llvm-project/pull/90214