Add missing "internal use" for register created for LoadAndInsertScal…

…ar() (#98814)

* Add internal use for LoadAndInsertScalar()

* Small cleanup

* Handle internal registers in constrained mode

* jit format

src/coreclr/jit/lsra.cpp

@@ -11745,8 +11745,7 @@ void LinearScan::verifyFinalAllocation()
             }
         }
 
-        LsraLocation newLocation = currentRefPosition.nodeLocation;
-        currentLocation          = newLocation;
+        currentLocation = currentRefPosition.nodeLocation;
 
         switch (currentRefPosition.refType)
         {

src/coreclr/jit/lsraarm64.cpp

@@ -1684,6 +1684,7 @@ int LinearScan::BuildHWIntrinsic(GenTreeHWIntrinsic* intrinsicTree, int* pDstCou
 
                 assert(intrinsicTree->OperIsMemoryLoadOrStore());
                 srcCount += BuildAddrUses(intrin.op3);
+                buildInternalRegisterUses();
                 FALLTHROUGH;
             }
 
@@ -2024,17 +2025,30 @@ bool RefPosition::isLiveAtConsecutiveRegistersLoc(LsraLocation consecutiveRegist
         return true;
     }
 
+    bool atConsecutiveRegsLoc          = consecutiveRegistersLocation == nodeLocation;
+    bool treeNeedsConsecutiveRegisters = false;
+
+    if ((treeNode != nullptr) && treeNode->OperIsHWIntrinsic())
+    {
+        const HWIntrinsic intrin(treeNode->AsHWIntrinsic());
+        treeNeedsConsecutiveRegisters = HWIntrinsicInfo::NeedsConsecutiveRegisters(intrin.id);
+    }
+
     if (refType == RefTypeDef)
     {
-        if (treeNode->OperIsHWIntrinsic())
+        return treeNeedsConsecutiveRegisters;
+    }
+    else if (refType == RefTypeUse)
+    {
+        if (isIntervalRef() && getInterval()->isInternal)
         {
-            const HWIntrinsic intrin(treeNode->AsHWIntrinsic());
-            return HWIntrinsicInfo::NeedsConsecutiveRegisters(intrin.id);
+            return treeNeedsConsecutiveRegisters;
         }
+        return atConsecutiveRegsLoc;
     }
-    else if ((refType == RefTypeUse) || (refType == RefTypeUpperVectorRestore))
+    else if (refType == RefTypeUpperVectorRestore)
     {
-        return consecutiveRegistersLocation == nodeLocation;
+        return atConsecutiveRegsLoc;
     }
     return false;
 }