[llvm] [AArch64][SVE] Implement demanded bits for @llvm.aarch64.sve.cntp (PR #168714)

[Paul Walker via llvm-commits]

================
@@ -19443,22 +19443,53 @@ AArch64TargetLowering::BuildSREMPow2(SDNode *N, const APInt &Divisor,
   return CSNeg;
 }
 
-static std::optional<unsigned> IsSVECntIntrinsic(SDValue S) {
+static bool IsSVECntIntrinsic(SDValue S) {
   switch(getIntrinsicID(S.getNode())) {
   default:
     break;
   case Intrinsic::aarch64_sve_cntb:
-    return 8;
   case Intrinsic::aarch64_sve_cnth:
-    return 16;
   case Intrinsic::aarch64_sve_cntw:
-    return 32;
   case Intrinsic::aarch64_sve_cntd:
-    return 64;
+  case Intrinsic::aarch64_sve_cntp:
+    return true;
   }
   return {};
----------------
paulwalker-arm wrote:

```suggestion
  return false;
```

https://github.com/llvm/llvm-project/pull/168714