/** The syscall dispatcher.
The should be called by subclasses when the syscall instruction is invoked.
<i>syscall</i> should be the contents of V0 and <i>a</i>, <i>b</i>, <i>c</i>, and <i>d</i> should be
the contenst of A0, A1, A2, and A3. The call MAY change the state
@see Runtime#state state */
/** The syscall dispatcher.
The should be called by subclasses when the syscall instruction is invoked.
<i>syscall</i> should be the contents of V0 and <i>a</i>, <i>b</i>, <i>c</i>, and <i>d</i> should be
the contenst of A0, A1, A2, and A3. The call MAY change the state
@see Runtime#state state */