Don't offer some functions from erlang module

[ignatov]

hello() ->
  spawn(1), % resolved
  erlang:spawn(1),
  md5("1"), % unresolved
  erlang:md5("1").

@kvakvs could you please tell me why md5 from erlang module is not resolved, but spawn is not?

[kvakvs]

this is located in erlang.erl which is "preloaded" i.e. baked into BEAM executable, intellij-erlang uses BIF map which is populated in some manual way instead org/intellij/erlang/bif/ErlangBifTable.java. Maybe some conflict here.

all resolutions work for me on master
possibly relies on availability of erlang.erl (located in lib/erts-12.0/src)