The difference is how we deal with intermediate fake overrides
E.g., in case
interface A { /* $1 */ fun foo() }
interface B : A {
/* $2 */ fake_override fun foo()
}
interface C : B {
/* $3 */ override fun foo()
}
We've got FIR declarations only for $1 and $3, but we've got
a fake override for $2 in IR.
Previously, override $3 had $1 as its overridden IR symbol, just because
FIR declaration of $3 doesn't know anything about $2.
Now, when generating IR for $2, we save the necessary information
and using it for $3, so it has $2 as overridden.
So, it's consistent with the overridden structure of FE 1.0 and this
structure is necessary prerequisite for proper building of bridges
for special built-ins.
For each non-abstract non-declared (i.e. inherited from supertypes) method in
an interface we generate its static form to the TImpl, which calls the TImpl
method from the corresponding supertype.
The accidental override tests changed because we're now trying to generate the
delegate for the super method, not knowing that it will clash with the declared
method
#KT-2888 Fixed
#KT-5393 Fixed