implement mangle.properties.domprops (#5686)

- support destructuring syntax
- fix corner case with comma operator

test/node.js

@@ -1,6 +1,6 @@
 var fs = require("fs");
 
-new Function("exports", require("../tools/node").FILES.map(function(file) {
+new Function("domprops", "exports", require("../tools/node").FILES.map(function(file) {
     if (/exports\.js$/.test(file)) file = require.resolve("./exports");
     return fs.readFileSync(file, "utf8");
-}).join("\n\n"))(exports);
+}).join("\n\n"))(require("../tools/domprops.json"), exports);