BUGS.txt

# Bug & design-limitation review of stackvm.c

All tracked correctness, missing-functionality, polish, and design-level
items have been addressed. This file is kept for the historical record;
see git log for the specific commits that fixed each.

## Resolved

- [x] A. No code-byte→instruction mapping kept. Resolved by the raw
  byte-stream refactor (fe4c07c): PC is now a byte offset, so syscalls,
  traces, and disassembly report native byte PCs that match q3asm's
  debug info directly. A dedicated ip_of[] is not needed.

- [x] B. code_mask / heap_mask forced power-of-two sizes. code[] stopped
  using a mask in the byte-stream refactor. Heap mask dropped in a
  follow-up: bounds-check against heap_len directly and round to a
  4-byte multiple instead of a pow2 (the only property the mask was
  enforcing for word-sized tail accesses).

- [x] Hardcoded VM_STACK_SIZE = 1024 op-stack words. Stack is now
  malloc'd per vm with default 1024; hosts that need more call
  vm_set_stack_size(vm, words) before the guest runs.