add utility methods for Kotlin code

java/java-impl/src/com/intellij/psi/util/pointers.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2000-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi.util
+
+import com.intellij.psi.PsiElement
+import com.intellij.psi.SmartPointerManager
+import com.intellij.psi.SmartPsiElementPointer
+
+fun <T : PsiElement> T.createSmartPointer(): SmartPsiElementPointer<T> {
+  return SmartPointerManager.getInstance(project).createSmartPsiElementPointer(this)
+}

java/java-impl/src/com/intellij/psi/util/psiTreeUtil.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2000-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi.util
+
+import com.intellij.psi.PsiElement
+
+inline fun <reified T : PsiElement> PsiElement.parentOfType(): T? {
+  return PsiTreeUtil.getParentOfType(this, T::class.java)
+}
+
+inline fun <reified T : PsiElement> PsiElement?.parentsOfType(): Sequence<T> {
+  return parentsOfType(T::class.java)
+}
+
+fun <T : PsiElement> PsiElement?.parentsOfType(clazz: Class<T>): Sequence<T> {
+  return generateSequence(this) { it.parent }.filterIsInstance(clazz)
+}