Remove pinning from frozen objects (strings, arrays, ..)

src/coreclr/jit/gentree.h

@@ -1084,7 +1084,18 @@ struct GenTree
 
     bool IsNotGcDef() const
     {
-        return IsIntegralConst(0) || OperIs(GT_LCL_ADDR);
+        if (IsIntegralConst(0) || OperIs(GT_LCL_ADDR))
+        {
+            return true;
+        }
+
+        // Any NonGC object or NonGC object + any offset.
+        if (IsIconHandle(GTF_ICON_OBJ_HDL) || (OperIs(GT_ADD) && gtGetOp1()->IsIconHandle(GTF_ICON_OBJ_HDL)))
+        {
+            return true;
+        }
+
+        return false;
     }
 
     // LIR flags

src/coreclr/jit/valuenum.cpp

@@ -15215,8 +15215,25 @@ void ValueNumStore::PeelOffsets(ValueNum* vn, target_ssize_t* offset)
 
     *offset = 0;
     VNFuncApp app;
-    while (GetVNFunc(*vn, &app) && (app.m_func == VNF_ADD))
+    while (GetVNFunc(*vn, &app) && ((app.m_func == VNF_ADD) || (app.m_func == VNF_Cast)))
     {
+        if (app.m_func == VNF_Cast)
+        {
+            // Ignore GC -> I_IMPL casts during peeling
+            if (TypeOfVN(*vn) == TYP_I_IMPL)
+            {
+                var_types castToType;
+                bool      srcIsUnsigned;
+                GetCastOperFromVN(app.m_args[1], &castToType, &srcIsUnsigned);
+                if (varTypeIsI(castToType) && varTypeIsI(TypeOfVN(app.m_args[0])))
+                {
+                    *vn = app.m_args[0];
+                    continue;
+                }
+            }
+            break;
+        }
+
         // We don't treat handles and null as constant offset.
 
         if (IsVNConstantNonHandle(app.m_args[0]) && (app.m_args[0] != VNForNull()))