Weaken assert around folding constants (dotnet#103026)

I ran into this assert with native AOT. It seems to be too strong - we are not allowed to fold IconHandle constants with prejit.

src/coreclr/jit/morph.cpp

@@ -9426,7 +9426,8 @@ GenTree* Compiler::fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac, bool* optA
             }
 
             /* Any constant cases should have been folded earlier */
-            noway_assert(!op1->OperIsConst() || opts.OptimizationDisabled() || optValnumCSE_phase);
+            noway_assert(!op1->OperIsConst() || op1->IsIconHandle() || opts.OptimizationDisabled() ||
+                         optValnumCSE_phase);
             break;
 
         case GT_CKFINITE: