FIR: implement -Xfriend-paths

compiler/testData/compileKotlinAgainstCustomBinaries/internalFromFriendModuleFir/library/a.kt

@@ -0,0 +1,15 @@
+package a
+
+internal interface InternalInterface
+
+public class PublicClass internal constructor() {
+    internal fun internalMemberFun() {}
+
+    internal companion object {}
+}
+
+internal val internalVal = ""
+
+internal fun internalFun(s: String): String = s
+
+internal typealias InternalTypealias = InternalInterface