Use normal VNs when adding NRE exception sets (dotnet#76639)

src/coreclr/jit/valuenum.cpp

@@ -10464,7 +10464,7 @@ void Compiler::fgValueNumberAddExceptionSetForIndirection(GenTree* tree, GenTree
     // We evaluate the baseAddr ValueNumber further in order
     // to obtain a better value to use for the null check exception.
     //
-    ValueNumPair baseVNP = baseAddr->gtVNPair;
+    ValueNumPair baseVNP = vnStore->VNPNormalPair(baseAddr->gtVNPair);
     ValueNum     baseLVN = baseVNP.GetLiberal();
     ValueNum     baseCVN = baseVNP.GetConservative();
     ssize_t      offsetL = 0;
@@ -10531,26 +10531,21 @@ void Compiler::fgValueNumberAddExceptionSetForIndirection(GenTree* tree, GenTree
         }
     }
 
-    // Create baseVNP, from the values we just computed,
-    baseVNP = ValueNumPair(baseLVN, baseCVN);
-
     // The exceptions in "baseVNP" should have been added to the "tree"'s set already.
-    assert(vnStore->VNPExcIsSubset(vnStore->VNPExceptionSet(tree->gtVNPair), vnStore->VNPExceptionSet(baseVNP)));
+    assert(vnStore->VNPExcIsSubset(vnStore->VNPExceptionSet(tree->gtVNPair),
+                                   vnStore->VNPExceptionSet(ValueNumPair(baseLVN, baseCVN))));
 
-    // The normal VN for base address is used to create the NullPtrExc
-    ValueNumPair vnpBaseNorm = vnStore->VNPNormalPair(baseVNP);
-    ValueNumPair excChkSet   = vnStore->VNPForEmptyExcSet();
+    // The normal VNs for base address are used to create the NullPtrExcs
+    ValueNumPair excChkSet = vnStore->VNPForEmptyExcSet();
 
-    if (!vnStore->IsKnownNonNull(vnpBaseNorm.GetLiberal()))
+    if (!vnStore->IsKnownNonNull(baseLVN))
     {
-        excChkSet.SetLiberal(
-            vnStore->VNExcSetSingleton(vnStore->VNForFunc(TYP_REF, VNF_NullPtrExc, vnpBaseNorm.GetLiberal())));
+        excChkSet.SetLiberal(vnStore->VNExcSetSingleton(vnStore->VNForFunc(TYP_REF, VNF_NullPtrExc, baseLVN)));
     }
 
-    if (!vnStore->IsKnownNonNull(vnpBaseNorm.GetConservative()))
+    if (!vnStore->IsKnownNonNull(baseCVN))
     {
-        excChkSet.SetConservative(
-            vnStore->VNExcSetSingleton(vnStore->VNForFunc(TYP_REF, VNF_NullPtrExc, vnpBaseNorm.GetConservative())));
+        excChkSet.SetConservative(vnStore->VNExcSetSingleton(vnStore->VNForFunc(TYP_REF, VNF_NullPtrExc, baseCVN)));
     }
 
     // Add the NullPtrExc to "tree"'s value numbers.