Update UglifyJS to 1.2.3

lib/uglify.js

@@ -115,6 +115,7 @@ var KEYWORDS = array_to_hash([
         "catch",
         "const",
         "continue",
+        "debugger",
         "default",
         "delete",
         "do",
@@ -143,7 +144,6 @@ var RESERVED_WORDS = array_to_hash([
         "byte",
         "char",
         "class",
-        "debugger",
         "double",
         "enum",
         "export",
@@ -1528,6 +1528,9 @@ function ast_walker() {
                 "function": function(name, args, body) {
                         return [ this[0], name, args.slice(), MAP(body, walk) ];
                 },
+                "debugger": function() {
+                        return [ this[0] ];
+                },
                 "defun": function(name, args, body) {
                         return [ this[0], name, args.slice(), MAP(body, walk) ];
                 },
@@ -2199,17 +2202,15 @@ function prepare_ifs(ast) {
 
                         var conditional = walk(fi[1]);
 
-                        var e_body = statements.slice(i + 1);
+                        var e_body = redo_if(statements.slice(i + 1));
                         var e = e_body.length == 1 ? e_body[0] : [ "block", e_body ];
 
-                        var ret = statements.slice(0, i).concat([ [
+                        return statements.slice(0, i).concat([ [
                                 fi[0],          // "if"
                                 conditional,    // conditional
                                 t,              // then
                                 e               // else
                         ] ]);
-
-                        return redo_if(ret);
                 }
 
                 return statements;
@@ -2928,6 +2929,7 @@ function gen_code(ast, options) {
                 "string": encode_string,
                 "num": make_num,
                 "name": make_name,
+                "debugger": function(){ return "debugger" },
                 "toplevel": function(statements) {
                         return make_block_statements(statements)
                                 .join(newline + newline);