Log Message:
openal-soft: Update to 1.20.1

openal-soft-1.20.1:

    Implemented the AL_SOFT_direct_channels_remix extension. This extends
    AL_DIRECT_CHANNELS_SOFT to optionally remix input channels that don't have
    a matching output channel.

    Implemented the AL_SOFT_bformat_ex extension. This extends B-Format buffer
    support for N3D or SN3D scaling, or ACN channel ordering.

    Fixed a potential voice leak when a source is started and stopped or
    restarted in quick succession.

    Fixed a potential device reset failure with JACK.

    Improved handling of unsupported channel configurations with WASAPI. Such
    setups will now try to output at least a stereo mix.

    Improved clarity a bit for the HRTF second-order ambisonic decoder.

    Improved detection of compatible layouts for SOFA files in makemhr and
    sofa-info.

    Added the ability to resample HRTFs on load. MHR files no longer need to
    match the device sample rate to be usable.

    Added an option to limit the HRTF's filter length.