[clang] [llvm] [AArch64] Decouple feature dependency expansion. (PR #94279)

[Tomas Matheson via cfe-commits]

================
@@ -13665,9 +13665,9 @@ QualType ASTContext::getCorrespondingSignedFixedPointType(QualType Ty) const {
 }
 
 // Given a list of FMV features, add each of their backend features to the list.
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tmatheson-arm wrote:

```suggestion
// Given a list of FMV features, return a concatenated list of the corresponding
// backend features (which might contain duplicates).
```

https://github.com/llvm/llvm-project/pull/94279