The injected field is defined as:

```
  macro(jdk_internal_vm_StackChunk, pc, intptr_signature, false) \
```

...yet it is read and written as "long", which silently overwrites adjacent fields in StackChunk on 32-bit platforms. This is a blocker for any 32-bit support. There are plenty of other `intptr` injected fields in other classes (e.g. `Class::array_klass`), and they are properly accessed by "address" accessors.