[Ohrrpgce] SVN: teeemcee/12201 Add music_sdl2.bas wrapper, to avoid global -d SDL_MIXER2 define

[subversion at HamsterRepublic.com]

teeemcee
2021-01-29 20:07:36 -0800 (Fri, 29 Jan 2021)
129
Add music_sdl2.bas wrapper, to avoid global -d SDL_MIXER2 define

That caused every .bas to be recompiled when switching backends
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U   wip/SConscript
U   wip/music_sdl.bas
A   wip/music_sdl2.bas
U   wip/sdl_lumprwops.bas