FIR: Implement FE 1.0 semantics for super unqualified calls

See original logic at org.jetbrains.kotlin.types.expressions.unqualifiedSuper.UnqualifiedSuperKt#resolveUnqualifiedSuperFromExpressionContext

^KT-39070 Fixed
^KT-39599 Related

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt

@@ -138,6 +138,10 @@ sealed class FirFakeSourceElementKind : FirSourceElementKind() {
     // a ?: b --> when(val $subj = a) { .... }
     // where `val $subj = a` has a fake source
     object WhenGeneratedSubject : FirFakeSourceElementKind()
+
+    // super.foo() --> super<Supertype>.foo()
+    // where `Supertype` has a fake source
+    object SuperCallImplicitType : FirFakeSourceElementKind()
 }
 
 sealed class FirSourceElement {