Added an example of an empty case label to avoid confusion.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164055 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LanguageExtensions.html b/docs/LanguageExtensions.html
index 79fd3bc..21ac627 100644
--- a/docs/LanguageExtensions.html
+++ b/docs/LanguageExtensions.html
@@ -1582,7 +1582,8 @@
 <pre>
 // compile with -Wimplicit-fallthrough
 switch (n) {
-case 33:
+case 22:
+case 33:  // no warning: no statements between case labels
   f();
 case 44:  // warning: unannotated fall-through
   g();