JIT: Add a pass of liveness for the new locals inside physical promotion

src/coreclr/jit/CMakeLists.txt

@@ -160,6 +160,7 @@ set( JIT_SOURCES
   phase.cpp
   promotion.cpp
   promotiondecomposition.cpp
+  promotionliveness.cpp
   rangecheck.cpp
   rationalize.cpp
   redundantbranchopts.cpp

src/coreclr/jit/compiler.h

@@ -513,6 +513,10 @@ class LclVarDsc
     {
         return lvTracked && lvType != TYP_STRUCT;
     }
+#ifdef DEBUG
+    unsigned char lvTrackedWithoutIndex : 1; // Tracked but has no lvVarIndex (i.e. only valid GTF_VAR_DEATH flags, used
+                                             // by physical promotion)
+#endif
     unsigned char lvPinned : 1; // is this a pinned variable?
 
     unsigned char lvMustInit : 1; // must be initialized

src/coreclr/jit/gentree.cpp

@@ -11936,7 +11936,6 @@ void Compiler::gtDispLocal(GenTreeLclVarCommon* tree, IndentStack* indentStack)
                     printf(" ");
                     fieldVarDsc->PrintVarReg();
                 }
-
                 if (fieldVarDsc->lvTracked && fgLocalVarLivenessDone && tree->IsLastUse(index))
                 {
                     printf(" (last use)");
@@ -11946,7 +11945,8 @@ void Compiler::gtDispLocal(GenTreeLclVarCommon* tree, IndentStack* indentStack)
     }
     else // a normal not-promoted lclvar
     {
-        if (varDsc->lvTracked && fgLocalVarLivenessDone && ((tree->gtFlags & GTF_VAR_DEATH) != 0))
+        if ((varDsc->lvTracked || varDsc->lvTrackedWithoutIndex) && fgLocalVarLivenessDone &&
+            ((tree->gtFlags & GTF_VAR_DEATH) != 0))
         {
             printf(" (last use)");
         }

src/coreclr/jit/lclvars.cpp

@@ -3564,6 +3564,7 @@ void Compiler::lvaSortByRefCount()
 
         // Start by assuming that the variable will be tracked.
         varDsc->lvTracked = 1;
+        INDEBUG(varDsc->lvTrackedWithoutIndex = 0);
 
         if (varDsc->lvRefCnt(lvaRefCountState) == 0)
         {