handle semicolons in "introduce backing property"

#KT-9417 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/IntroduceBackingPropertyIntention.kt

@@ -89,13 +89,18 @@ class IntroduceBackingPropertyIntention(): JetSelfTargetingIntention<JetProperty
         private fun createGetter(element: JetProperty) {
             val body = "get() = _${element.name}"
             val newGetter = JetPsiFactory(element).createProperty("val x $body").getter!!
-            element.add(newGetter)
+            element.addAccessor(newGetter)
         }
 
         private fun createSetter(element: JetProperty) {
             val body = "set(value) { _${element.name} = value }"
             val newSetter = JetPsiFactory(element).createProperty("val x $body").setter!!
-            element.add(newSetter)
+            element.addAccessor(newSetter)
+        }
+
+        private fun JetProperty.addAccessor(newAccessor: JetPropertyAccessor) {
+            val semicolon = getNode().findChildByType(JetTokens.SEMICOLON)
+            addBefore(newAccessor, semicolon?.psi)
         }
 
         private fun createBackingProperty(property: JetProperty) {

idea/testData/intentions/introduceBackingProperty/semicolon.kt

@@ -0,0 +1,3 @@
+class City(val name: String) {
+    var ti<caret>meZone : Int = -3;
+}

idea/testData/intentions/introduceBackingProperty/semicolon.kt.after

@@ -0,0 +1,8 @@
+class City(val name: String) {
+    private var _timeZone: Int = -3
+    var timeZone : Int
+        get() = _timeZone
+        set(value) {
+            _timeZone = value
+        };
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -5268,6 +5268,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("semicolon.kt")
+        public void testSemicolon() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/intentions/introduceBackingProperty/semicolon.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("simpleVal.kt")
         public void testSimpleVal() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/testData/intentions/introduceBackingProperty/simpleVal.kt");