IDEA-178141 Case sensitive completion: First Letter - doesn't work correctly if class starts with special symbol

check first letter after the underscore

java/java-tests/testData/codeInsight/completion/normalSorting/DispreferUnderscoredCaseMatch.java

@@ -0,0 +1,5 @@
+class Zoo {
+  void zoo(String fooBar, String __foo_bar) {
+    foo<caret>
+  }
+}