x86_64 is used as a baseline: the "x86_64" entry, whatever status it has,
is transformed into "all", and then the other entries in ARCHITECTURES
either dropped or rearranged appropriately.
* atari800_libretro: bumped to version 3.1.0:20200921
* bluemsx_libretro: bumped to version 2.9.0:20200920
* cap32_libretro: bumped to version 4.2.0:20200923
* fmsx_libretro: bumped to version 4.9:20200920
* mrboom_libretro: bumped to version 4.9:20200923
* fbneo_libretro: bumped to version 0.2.97.44:20200925
* fceumm_libretro: bumped to version 0.0.1:20200909
* flycast_libretro: bumped to version 0.1:20200923
* freeintv_libretro: bumped to version 0.0:20200721
* gambatte_libretro: bumped to version 0.5.0:20200922
* genesis_plus_gx_libretro: bumped to version 1.7.4:20200717
* gpsp_libretro: bumped to version 0.91:20200921
* handy_libretro: bumped to version 0.95:20200913
* mednafen_gba_libretro: bumped to version 0.9.36:20200818
* mednafen_lynx_libretro: bumped to version 0.9.32:20200919
* mednafen_ngp_libretro: bumped to version 0.9.36.1:20200924
* mednafen_pce_fast_libretro: bumped to version 0.9.38.7:20200924
* mednafen_pce_libretro: bumped to version 0.9.38.7:20200924
* mednafen_pcfx_libretro: bumped to version 0.9.33.3:20200922
* mednafen_psx_hw_libretro: bumped to version 0.9.38.6:20200924
* mednafen_psx_libretro: bumped to version 0.9.39.2:20200924
* mednafen_saturn_libretro: bumped to version 0.9.45.1:20200924
* mednafen_supergrafx_libretro: bumped to version 0.9.38.7:20200925
* mednafen_vb_libretro: bumped to version 0.9.36.1:20200924
* mednafen_wswan_libretro: bumped to version 0.9.35.1:20200924
* mgba_libretro: bumped to version 0.6.1:20200922
* o2em_libretro: bumped to version 1.18:20200913
* opera_libretro: bumped to version 1.0.0:20200711
* parallel_n64_libretro: bumped to version 2.0rc2:20200818
* pcsx_rearmed_libretro: bumped to version r22:20200910
* picodrive_libretro: bumped to version 1.92:20200816
* snes9x_libretro: bumped to version 1.60:20200916
* vba_next_libretro: bumped to version 1.0.2:20200916
* vecx_libretro: bumped to version 1.2:20200916
* virtualjaguar_libretro: bumped to version 2.1.2:20200917
* reminiscence_libretro: bumped to version 0.3.6:20200917
* craft_libretro: bumped to version 1.0:20200725