Getting completions when writing out a dot in a parameter should suggest the splat operator

At present the completions returned seem arbitrary. Example:

function(arg: string, ./**/): any {
}

Getting completions at the marker yields the typical alphabetical list of global things - worse yet, in VSCode, pressing . again auto-completes the first one (.AbstractWorker. isn't really a valid argument name)! Very frustrating.

复现参数示例中标记处的补全行为，包括 VSCode 中按下 . 会选择第一个全局建议的情况。跟踪参数中点号对应的 TypeScript 补全路径，并使补全建议包含 splat 运算符，而不是任意的全局名称；验证无效结果 .AbstractWorker. 不再出现。