Emulator

How integer overflow in _MALLOC() happens in C emulator memory allocation and how to fix it

A critical integer overflow vulnerability was discovered in `i286c/i286c.c` at line 216, where the expression `_MALLOC(size + 16)` could wrap around to a tiny value when `size` approaches `UINT32_MAX`. This undersized allocation leads to a massive heap buffer overflow when the emulator writes the expected number of bytes. The fix adds a simple overflow guard that checks whether `size + 16` would wrap before performing the allocation.