Support getting call site position of a function

Consider this example:
```
fun test(lineNumber: Int = __LINE__) {
println("$lineNumber")
}

test()
test()
```
It prints the same value twice. This means that it's impossible to get a call site position of a function using Cite. It's supported in Swift.

Start with the issue's Kotlin example and inspect the Cite compiler plugin's handling of __LINE__. Compare the requested call-site behavior with the existing function-default behavior and determine what compiler information must be preserved; done means repeated test() calls report their distinct call-site positions.

Written by the indexing model from the issue text.