Change GC stack slot negative hex offsets to show as negative (#45940)

Change GC stack slot negative hex offsets to show as negative (#45940)

In the GC output, instead of:

```
Stack slot id for offset -104 (0xffffff98) (frame) = 5.
```

display:

```
Stack slot id for offset -104 (-0x68) (frame) = 5.
```

This makes it easier to search for or visually match the
`-0x68` against asm like:
```
mov      gword ptr [rbp-68H], rax
```