Function references are now equal if they refer to the same function,
and if the parameter/return type adaptation, which happens when a
reference is used where some function type is expected, is exactly the
same. This includes the number of expected positional parameters (which
can be affected by defaults/varargs), whether the coercion of vararg
parameter to Array type happened, and whether the coercion of return
type to Unit happened.
#KT-37543 Fixed
Vitaly