CommentTracker: do not add a comment as a first child of PsiElement

Fixes IDEA-187526 "Add static import" with an intervening comment leads to exception

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/addSingleStaticImport/LineComment.java

@@ -0,0 +1,8 @@
+class X {
+
+  public static void main(String[] args) {
+    System.out.println("took " + (System//simple end comment
+                                    .currentTi<caret>meMillis() - 1) + "ms");
+  }
+
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/addSingleStaticImport/LineComment_after.java

@@ -0,0 +1,10 @@
+import static java.lang.System.currentTimeMillis;
+
+class X {
+
+  public static void main(String[] args) {
+    System.out.println("took " + (//simple end comment
+            currentTimeMillis() - 1) + "ms");
+  }
+
+}