[llvm] [SPARC][IAS] Properly set implied feature sets for ISA levels/extensions (PR #143232)

[Fangrui Song via llvm-commits]

================
@@ -1,20 +1,12 @@
 # RUN: llvm-mc %s -triple=sparc | FileCheck %s --check-prefix=ASM
----------------
MaskRay wrote:

It's usually easier to maintain to test different ISAs with the same test file.
You can use
```
--check-prefixes=OBJDUMP,OBJDUMP-V8
--check-prefixes=OBJDUMP,OBJDUMP-V9
```


https://github.com/llvm/llvm-project/pull/143232