* Bump submodule and generate std headers
* Commit submodule update
* Downgrade to earlier commit
Can be upgraded once a proper C++20 MinGW compiler
is available for the docker images.
* Downgrade to the correct commit
* Append mingw_stdthreads to EXTRA_LIBRARIES
Currently for this CMake version, it seems that there is no support to
link other targets to object libraries. I'll add it to EXTRA_LIBRARIES
instead.
* Add LMMS_ prefix to USE_MINGW_STD_THREADS
* Use built-in MINGW CMake variable
* Use lowercase rather than uppercase
2ca05d025c