[Ohrrpgce] SVN: teeemcee/10337 Some cleanup of enemy death code

[subversion at HamsterRepublic.com]

teeemcee
2018-04-06 23:57:17 -0700 (Fri, 06 Apr 2018)
214
Some cleanup of enemy death code

Split out enemy_death_sfx

I added a couple checks to skip empty hero slots which have no effect on
behaviour, such as not doing death processing for nonexistent heroes every tick.
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U   wip/bmod.bi
U   wip/bmod.rbas