bug with cast #371

```cpp
int printf(const char *, ...);
char t[] = {0, 0, 0, 0};

void show() {
  for (int i = 0; i < 4; i++)
    printf("%d ", t[i]);
  printf("\n");
}

int main(void) {
  char *data = t;
  show();
  *(data) -= 2;
  show();
  *(unsigned *)(data) -= 2;
  show();
  return 0;
}
```