a LabeledStatement should be in fact a StatementWithBody

This fixes output for:

    if (foo) {
        moo: if (bar) {
            break moo;
        }
    } else {
        baz();
    }

(the labeled statement must be outputted inside brackets)

lib/parse.js

@@ -892,7 +892,7 @@ function parse($TEXT, exigent_mode) {
         S.labels.push(label);
         var start = S.token, stat = statement();
         S.labels.pop();
-        return new AST_LabeledStatement({ statement: stat, label: label });
+        return new AST_LabeledStatement({ body: stat, label: label });
     };
 
     function simple_statement() {