Do you know what minecraft java version this was introduced?
Prism Launcher's MC 1.12.2 lwjgl-platform-2.9.4-nightly-20150209 has OpenAL DLLs with metadata dates of 2013/04/07.
Do you think simply repacking the DLLs in this jar and adding an `alsoft.ini` with `hrtf = true` would work? I'll try soon.
Edit: Looks like MC uses a paulscode OpenAL implementation dated 2010/08/24. Doesn't look trivial to replace.