"Find Usages": separate Kotlin and Java tests

idea/testData/findUsages/kotlin/findFunctionUsages/javaMethodUsages.0.kt

@@ -0,0 +1,11 @@
+// PSI_ELEMENT: org.jetbrains.jet.lang.psi.JetNamedFunction
+// OPTIONS: usages
+package testing;
+
+public open class Server() {
+    public open fun <caret>processRequest() = "foo"
+}
+
+public class ServerEx(): Server() {
+    public override fun processRequest() = "foofoo"
+}