message: Add comment on `emit_nop_n`.
diff: @@ -77,6 +77,9 @@ pub trait Emitter {
  fn emit_label(&mut self, label: Self::Label);
  fn emit_nop(&mut self);
  +
  + /// A high-level assembler method. Emits an instruction sequence of length `n` that is functionally
  + /// equivalent to a `nop` instruction, without guarantee about the underlying implementation.
  fn emit_nop_n(&mut self, n: usize);
  fn emit_mov(&mut self, sz: Size, src: Location, dst: Location);
  