[clang] [compiler-rt] [llvm] [FMV][AArch64] Unify ls64, ls64_v and ls64_accdata. (PR #108024)

[via cfe-commits]

================
@@ -73,8 +73,6 @@ enum CPUFeatures {
   FEAT_SSBS,
   FEAT_SSBS2,
   FEAT_BTI,
-  FEAT_LS64,
-  FEAT_LS64_V,
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Wilco1 wrote:

We **absolutely** must keep the values the same since they are now ABI and used in the ifunc resolvers in the object files:

```
        bl      __init_cpu_features_resolver
        adrp    x0, __aarch64_cpu_features
        ldr     x0, [x0, #:lo12:__aarch64_cpu_features]
        tbnz    x0, 36, .L8
```

The 36 is from the enum, now imagine a new compiler release changing it to 35 or a different compiler using 40...

https://github.com/llvm/llvm-project/pull/108024