To remove un-used variable

Author: xuemingshen-oracle

src/java.base/share/classes/java/lang/String.java

@@ -3887,6 +3887,7 @@ public String toUpperCase() {
      */
 
     public String toCaseFold() {
+        System.out.println("String.toCaseFold()");
         return isLatin1() ? StringLatin1.toCaseFold(this, value)
                           : StringUTF16.toCaseFold(this, value);
     }

test/jdk/java/lang/String/TestStringToCaseFold.java

@@ -0,0 +1,5 @@
+public class TestStringToCaseFold {
+    public static void main(String[] args) throws Exception {
+        System.out.println("A\u00dfbc".toCaseFold());
+    }
+}

test/jdk/java/lang/String/UnicodeCaseFoldingTest.java

@@ -43,8 +43,6 @@
 
 public class UnicodeCaseFoldingTest {
 
-    private Object[] strs;
-
     @Test
     void testAllCodePointsListedInCaseFoldinigTxt() throws Throwable {
         var filter = "^.*; [CF]; .*$";  // C=common, F=full, for full case folding