Fix restore vao bug bewteen js and native

[bliu96]

GL object is managed by wasm js scipt, Each GL object created in native has an unique id generated in wasm.js.

wasm.js

var _glGenBuffers = (n, buffers) => {
  __glGenObject(n, buffers, 'createBuffer', GL.buffers
    );
};

var __glGenObject = (n, buffers, createFunction, objectTable) => {
  for (var i = 0; i < n; i++) {
    var buffer = GLctx[createFunction]();
    var id = buffer && GL.getNewId(objectTable);
    if (buffer) {
      buffer.name = id;
      objectTable[id] = buffer;
    } else {
      GL.recordError(0x502 /* GL_INVALID_OPERATION */);
    }
    HEAP32[(((buffers)+(i*4))>>2)] = id;
  }
 };


var _glGetIntegerv = (name_, p) => {
   emscriptenWebGLGet(name_, p, 0);
};

var emscriptenWebGLGet = (name_, p, type) => {
    ...
    var result = GLctx.getParameter(name_);
    ...
    ret = result.name | 0;
    ...
}

This explains why create and bind buffer in js but get 0 in native glGetIntegerv.