Added tests with class/function used in Java

idea/testData/inspections/unusedSymbol/class/usedInJava.java

@@ -0,0 +1,5 @@
+class RandomJavaClass {
+    void f(foo.UsedInJava p) {
+
+    }
+}

idea/testData/inspections/unusedSymbol/class/usedInJava.kt

@@ -0,0 +1,3 @@
+package foo
+
+class UsedInJava

idea/testData/inspections/unusedSymbol/function/usedInJava.java

@@ -0,0 +1,5 @@
+class RandomJavaClass {
+    void g() {
+        foo.FooPackage.usedInJava();
+    }
+}

idea/testData/inspections/unusedSymbol/function/usedInJava.kt

@@ -0,0 +1,4 @@
+package foo
+
+fun usedInJava() {
+}

idea/tests/org/jetbrains/kotlin/idea/codeInsight/AbstractJetInspectionTest.kt

@@ -53,7 +53,7 @@ public abstract class AbstractJetInspectionTest: LightCodeInsightFixtureTestCase
             setTestDataPath("${JetTestUtils.getHomeDirectory()}/$srcDir")
 
             val psiFiles = srcDir
-                    .listFiles { it.getName().endsWith(".kt") || it.getName().endsWith(".txt") || it.getName().endsWith(".xml") }!!
+                    .listFiles { it.getName().endsWith(".kt") || it.getName().endsWith(".txt") || it.getName().endsWith(".xml") || it.getName().endsWith(".java") }!!
                     .map {
                         file ->
                         val text = FileUtil.loadFile(file, true)