Clear IconHandle when we fold compares

Fixes dotnet#95367.

Relevant part of the JitDump:

```
Using `if true` assertions from pred BB02
Assertions in: #1
fgMorphTree BB04, STMT00021 (before)
               [000070] DA---------                         *  STORE_LCL_VAR ubyte  V10 tmp9
               [000057] -----------                         \--*  CAST      int <- ubyte <- int
               [000006] -----------                            \--*  EQ        int
               [000004] -----------                               +--*  LCL_VAR   ref    V02 tmp1          (last use)
               [000055] H----------                               \--*  CNS_INT(h) ref     'Frozen EmptyPartition`1<Int32> object'

Assertion prop for index #1 in BB04:
               [000006] -----------                         *  EQ        int
GenTreeNode creates assertion:
               [000070] DA---+-----                         *  STORE_LCL_VAR ubyte  V10 tmp9
In BB04 New Local Constant Assertion: V10 == [0000000000000001], index = #2

fgMorphTree BB04, STMT00021 (after)
               [000070] DA---+-----                         *  STORE_LCL_VAR ubyte  V10 tmp9
               [000055] H----+-----                         \--*  CNS_INT(h) int
```

The JitDump is unfinished because the compiler crashes when trying to dump the last line. Clearly, the `CNS_INT` is no longer a handle at that point because we just bashed it to a constant 1.

src/coreclr/jit/assertionprop.cpp

@@ -4358,6 +4358,7 @@ GenTree* Compiler::optAssertionPropLocal_RelOp(ASSERT_VALARG_TP assertions, GenT
 
     op2->AsIntCon()->gtIconVal = foldResult;
     op2->gtType                = TYP_INT;
+    op2->ClearIconHandleMask();
 
     return optAssertionProp_Update(op2, tree, stmt);
 }