This still needs some expansion.

  - ma_factor_to_gain_db > ma_volume_linear_to_db
  - ma_gain_db_to_factor > ma_volume_db_to_linear

This fixes some warnings when compiling with Clang on Windows.

This change forces correct alignment of variables marked as atomic.

This includes a leading trimming node to act as a test.

This is hopefully a temporary measure to address a bug in the lock-free
algorithm.

Fixed compiling for iOS 11.x and earlier