Performance: hoist String fast-path above null check in hashCodeIgnoreCase(CharSequence)

The original ordering tested `cs == null` first, then checked `cs instanceof String`
to delegate to the optimized String-specific overload. Since `null instanceof String`
is false, the null branch is never taken on the String path and adds a wasted
comparison on what is by far the most common input type. Reordering so the
String-dispatch runs first preserves null-safety (null instanceof String == false
leaves the null check in place for non-String inputs) and removes one branch on
the hot path. Pure reordering, no behavioral change.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Claude Opus 4.7 (1M context)

src/main/java/com/cedarsoftware/util/StringUtilities.java

@@ -990,13 +990,13 @@ public static String createString(byte[] bytes, String encoding) {
      * @return the case-insensitive hash code, or 0 if cs is null
      */
     public static int hashCodeIgnoreCase(CharSequence cs) {
-        if (cs == null) return 0;
-
         // For String, delegate to the optimized String-specific version
         if (cs instanceof String) {
             return hashCodeIgnoreCase((String) cs);
         }
 
+        if (cs == null) return 0;
+        
         // Single-pass optimization with ASCII fast path.
         final int n = cs.length();
         int h = 0;