Fix 'Formatting after braceless class declaration' (KT-3858)

It's irrelevant that element is incompleted when new node is being add to the middle

 #KT-3858

idea/src/org/jetbrains/jet/plugin/formatter/JetBlock.java

@@ -168,8 +168,12 @@ public class JetBlock extends AbstractBlock {
             return super.getChildAttributes(newChildIndex);
         }
 
-        if (isIncomplete()) {
-            return super.getChildAttributes(newChildIndex);
+        List<Block> blocks = getSubBlocks();
+        if (newChildIndex != 0) {
+            boolean isIncomplete = newChildIndex < blocks.size() ? blocks.get(newChildIndex - 1).isIncomplete() : isIncomplete();
+            if (isIncomplete) {
+                return super.getChildAttributes(newChildIndex);
+            }
         }
 
         return new ChildAttributes(Indent.getNoneIndent(), null);

idea/testData/indentationOnNewline/AfterClassNameBeforeFun.after.kt

@@ -0,0 +1,4 @@
+class A()
+<caret>
+
+fun

idea/testData/indentationOnNewline/AfterClassNameBeforeFun.kt

@@ -0,0 +1,3 @@
+class A()<caret>
+
+fun

idea/tests/org/jetbrains/jet/formatter/JetTypingIndentationTestBaseGenerated.java

@@ -40,6 +40,11 @@ public class JetTypingIndentationTestBaseGenerated extends AbstractJetTypingInde
             doNewlineTest("idea/testData/indentationOnNewline/AfterCatch.after.kt");
         }
         
+        @TestMetadata("AfterClassNameBeforeFun.after.kt")
+        public void testAfterClassNameBeforeFun() throws Exception {
+            doNewlineTest("idea/testData/indentationOnNewline/AfterClassNameBeforeFun.after.kt");
+        }
+        
         @TestMetadata("AfterFinally.after.kt")
         public void testAfterFinally() throws Exception {
             doNewlineTest("idea/testData/indentationOnNewline/AfterFinally.after.kt");