hygiene, provide debugging info that makes sense in utesort.c's load_runs()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide truefx stream file muxer

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, actually assign idx values from ute_sym2idx()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'cmd/mux-truefx' into next

* cmd/mux-truefx:
  minor, actually assign idx values from ute_sym2idx()
  minor, provide truefx stream file muxer
Merge branch 'next'

* next:
  minor, actually assign idx values from ute_sym2idx()
  minor, provide truefx stream file muxer
  hygiene, provide debugging info that makes sense in utesort.c's load_runs()