Fix a few input locations from within music functions

Fix a few input locations from within music functions


Contains commits:

Add override_input to music created from loc_on_music

This makes sure that music created from default arguments of function
calls appears to generate from surrounding music function calls rather
than the music function body.

Add location info override to some music expressions

This gives location information for #{ ... #} to music function callers
instead of the music function body.