[llvm] [AArch64] Allow single-element vector FP converts with +fprcvt (PR #169692)

[via llvm-commits]

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@@ -329,8 +329,8 @@ def HasNEONandIsStreamingSafe
     : Predicate<"Subtarget->hasNEON()">,
       AssemblerPredicateWithAll<(any_of FeatureNEON), "neon">;
 // A subset of NEON instructions are legal in Streaming SVE mode only with +sme2p2.
-def HasNEONandIsSME2p2StreamingSafe
-                     : Predicate<"Subtarget->isNeonAvailable() || (Subtarget->hasNEON() && Subtarget->hasSME2p2())">,
+def HasNEONandFPRCVTIsStreamingSafe
+                     : Predicate<"Subtarget->isNeonAvailable() || (Subtarget->hasNEON() && Subtarget->isFPRCVTStreamingSafe())">,
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Lukacma wrote:

why not just use this ?

```suggestion
                     : Predicate<"Subtarget->isNeonAvailable() || (Subtarget->hasNEON() && Subtarget->hasFPRCVT())">,
```

https://github.com/llvm/llvm-project/pull/169692