message: Fix build with latest Rust nightly compiler.
  Pointer addresses must always be usize, even if we know that they are going to be 64-bits wide!
diff: @@ -46,41 +46,41 @@ extern "C" {
  #[repr(C, packed)]
  struct State {
  /// FS register for TLS support
  - fs: u64,
  + fs: usize,
  /// R15 register
  - r15: u64,
  + r15: usize,
  /// R14 register
  - r14: u64,
  + r14: usize,
  /// R13 register
  - r13: u64,
  + r13: usize,
  /// R12 register
  - r12: u64,
  + r12: usize,
  /// R11 register
  - r11: u64,
  + r11: usize,
  /// R10 register
  - r10: u64,
  + r10: usize,
  /// R9 register
  - r9: u64,
  + r9: usize,
  /// R8 register
  - r8: u64,
  + r8: usize,
  /// RDI register
  - rdi: u64,
  + rdi: usize,
  /// RSI register
  - rsi: u64,
  + rsi: usize,
  /// RBP register
  - rbp: u64,
  + rbp: usize,
  /// RBX register
  - rbx: u64,
  + rbx: usize,
  /// RDX register
  - rdx: u64,
  + rdx: usize,
  /// RCX register
  - rcx: u64,
  + rcx: usize,
  /// RAX register
  - rax: u64,
  + rax: usize,
  /// status flags
  - rflags: u64,
  + rflags: usize,
  /// instruction pointer
  - rip: u64
  + rip: usize
  }
  pub struct TaskStacks {
  @@ -179,24 +179,24 @@ impl TaskFrame for Task {
  ptr::write_bytes(self.stacks.stack as *mut u8, 0xCD, DEFAULT_STACK_SIZE);
  // Set a marker for debugging at the very top.
  - let mut stack = (self.stacks.stack + DEFAULT_STACK_SIZE - 0x10) as *mut u64;
  - *stack = 0xDEADBEEFu64;
  + let mut stack = (self.stacks.stack + DEFAULT_STACK_SIZE - 0x10) as *mut usize;
  + *stack = 0xDEADBEEFusize;
  // Put the leave_task function on the stack.
  // When the task has finished, it will call this function by returning.
  - stack = (stack as usize - mem::size_of::<u64>()) as *mut u64;
  - *stack = leave_task as u64;
  + stack = (stack as usize - mem::size_of::<usize>()) as *mut usize;
  + *stack = leave_task as usize;
  // Put the State structure expected by the ASM switch() function on the stack.
  - stack = (stack as usize - mem::size_of::<State>()) as *mut u64;
  + stack = (stack as usize - mem::size_of::<State>()) as *mut usize;
  let state = stack as *mut State;
  ptr::write_bytes(state as *mut u8, 0, mem::size_of::<State>());
  - (*state).rip = task_entry as u64;
  - (*state).rdi = func as u64;
  - (*state).rsi = arg as u64;
  - (*state).rflags = 0x1202u64;
  + (*state).rip = task_entry as usize;
  + (*state).rdi = func as usize;
  + (*state).rsi = arg as usize;
  + (*state).rflags = 0x1202usize;
  // Set the task's stack pointer entry to the stack we have just crafted.
  self.last_stack_pointer = stack as usize;
  