A follow-up for KT-35006:
fun f() = foo {
bar()
}
inline fun foo(crossinline x: () -> Unit) = { x() }()
inline fun bar() = TODO()
does not provide the option to navigate to bar's call site at all.
* a writing source mapper has `mapLineNumber(line, file, class)` that
inserts a new SMAP entry and returns a fake line number from it;
* a copying source mapper has `mapLineNumber(line)` that uses an
existing SMAP to resolve the line number and call the former method
on a different source mapper;
* those two types are disjoint.
We should only insert a return statement at the end of a lambda or
function if the final statement is used as an expression (slice
USED_AS_RESULT_OF_LAMBDA and USED_AS_EXPRESSION).
Dmitry Petrov