fix bug: invoke overload method disorder

fix invoke java overload method disorder problem

src/jse/org/luaj/vm2/lib/jse/JavaMethod.java

@@ -114,8 +114,19 @@ class JavaMethod extends JavaMember {
 
 		final JavaMethod[] methods;
 
+		// no parammeter method index in overload method
+		int noArgMethodIndex = -1;
+		
 		Overload(JavaMethod[] methods) {
 			this.methods = methods;
+			JavaMethod m;
+			for (int i=0; i<methods.length; i++) {
+				m = methods[i];
+				if (m.fixedargs.length == 0 && m.varargs == null) {
+					noArgMethodIndex = i;
+					break;
+				}
+			}
 		}
 
 		public LuaValue call() {
@@ -140,6 +151,10 @@ class JavaMethod extends JavaMember {
 
 		private LuaValue invokeBestMethod(Object instance, Varargs args) {
 			JavaMethod best = null;
+			int n = args.narg();
+			if (n == 0 && noArgMethodIndex != -1) {
+				best = methods[noArgMethodIndex];
+			} else {
 				int score = CoerceLuaToJava.SCORE_UNCOERCIBLE;
 				for ( int i=0; i<methods.length; i++ ) {
 					int s = methods[i].score(args);
@@ -150,6 +165,7 @@ class JavaMethod extends JavaMember {
 							break;
 					}
 				}
+			}
 			
 			// any match? 
 			if ( best == null )