message: Mark OperandStack::bottom() noexcept
  It was already used in rbegin() which is marked noexcept
diff: @@ -75,9 +75,9 @@ class OperandStack
  /// The unbounded storage for items.
  std::unique_ptr<Value[]> m_large_storage;
  - Value* bottom() { return m_large_storage ? m_large_storage.get() : m_small_storage; }
  + Value* bottom() noexcept { return m_large_storage ? m_large_storage.get() : m_small_storage; }
  - const Value* bottom() const
  + const Value* bottom() const noexcept
  {
  return m_large_storage ? m_large_storage.get() : m_small_storage;
  }
  