Avoid global pollution of Function.prototype in Dart to JavaScript conversion for Node.js npm package

Hi,
I've noticed that when Dart code is compiled to JavaScript for building npm, it adds some methods to the Function.prototype, which causes global pollution. This can lead to potential conflicts with other libraries and unexpected behaviors. Here's an example of the problematic code:
```javascript
Function.prototype.$1 = function (a) { return this(a) }
Function.prototype.$0 = function () { return this() }
Function.prototype.$2 = function (a, b) { return this(a, b) }
// ... other similar methods
```
This approach modifies the global Function object, which is not considered a good practice. Instead, these methods should be encapsulated or implemented in a way that does not affect global objects.
Steps to Reproduce:
1、dart run grinder npm
2、Inspect the resulting JavaScript code in the build/node/gltf_validator.dart.js file, and you'll find the above-mentioned modifications to Function.prototype

Start by running `dart run grinder npm` and inspecting `build/node/gltf_validator.dart.js`, where the issue reports the Function.prototype additions. Trace the Dart-to-JavaScript npm build path to identify their source. Done means the generated Node.js bundle no longer modifies the global Function.prototype while retaining the required behavior.

Written by the indexing model from the issue text.