Fix usages of javaClass property

idea/tests/org/jetbrains/jet/plugin/libraries/AbstractDecompiledTextTest.kt

@@ -34,8 +34,7 @@ public abstract class AbstractDecompiledTextTest() : JetLightCodeInsightFixtureT
     public fun doTest(path: String) {
         val classFile = NavigateToDecompiledLibraryTest.getClassFile("test", getTestName(false), myModule!!)
         val clsFileForClassFile = PsiManager.getInstance(getProject()!!).findFile(classFile)
-        assertNotNull(clsFileForClassFile)
-        assertTrue("Expecting java class file, was: " + clsFileForClassFile.javaClass, clsFileForClassFile is ClsFileImpl)
+        assertTrue("Expecting java class file, was: " + clsFileForClassFile!!.javaClass, clsFileForClassFile is ClsFileImpl)
         val decompiledPsiFile = (clsFileForClassFile as ClsFileImpl).getDecompiledPsiFile()
         assertNotNull(decompiledPsiFile)
         assertSameLinesWithFile(path.substring(0, path.length - 1) + ".expected.kt", decompiledPsiFile!!.getText())

idea/tests/org/jetbrains/jet/plugin/libraries/InternalCompiledClassesTest.kt

@@ -59,7 +59,7 @@ public class InternalCompiledClassesTest : JetLightCodeInsightFixtureTestCase()
     fun testTraitImplClassIsVisibleAsJavaClass() {
         val project = getProject()!!
         doTest("trait impl", isSyntheticClassOfKind(TRAIT_IMPL)) {
-            val psiFile = PsiManager.getInstance(project).findFile(this)
+            val psiFile = PsiManager.getInstance(project).findFile(this)!!
             Assert.assertTrue("Should not be kotlin file",
                               psiFile !is JetClsFile)
             Assert.assertTrue("Should be java file, was ${psiFile.javaClass.getSimpleName()}",

libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/highlighter/HtmlKotlinVisitor.kt

@@ -48,7 +48,7 @@ class HtmlKotlinVisitor: JetTreeVisitor<StringBuilder>() {
                 if (child is PsiComment || child is PsiWhiteSpace) {
                     // ignore
                 } else {
-                    println("------- Child $child of type ${child.javaClass}")
+                    println("------- Child $child of type ${child?.javaClass}")
                 }
                 child?.accept(this)
             }