Give guest exception what, non-deleting destructor and deleting destructor slots explicit APS5_VABI types and register guest adapters. Preserve native helpers, object layouts, native exception routing and existing malloc/free ownership.
Add mismatched and cleared RCX regressions for plain and message vtables, observing actual libc free calls to reject foreign or duplicate frees. Retain typed guest catch/rethrow and native exception coverage. All 27 targeted CTests pass three repetitions on Windows Release; Linux execution remains unvalidated.
Guest message throws registered native Windows callbacks even though Release invokes guest callbacks using System V. Register an APS5_VABI adapter in the standard and regex message throw paths and retain the native DestroyMessage helper and legacy callback storage type.
Add MinGW CTest regressions with distinct or zero RCX, shared and final-release messages, typed guest catches, rethrow and normal Release. All ten new cases plus Windows exception and thread callback regressions pass three repetitions. Linux execution remains unvalidated; guest vtables and host exception paths are unchanged.
Prophet069