Chinese IME does not work correctly with CompletionItemProvider

If set suggestion label as a chinese text, the auto complete item will never show when input with chinese IME like sougou.

And I found that the suggestion check is triggered in 'compositionupdate' event instead of 'compositionend,' then the selection check is failed, the preSelection(typed alpha text) is after currentSelection(chinese text):

//  in suggestModel.js : _onCursorChange

(!prevSelection.containsRange(this._currentSelection) && !prevSelection.getEndPosition().isBeforeOrEqual(this._currentSelection.getPosition()))

In vscode there is same problem. the snippets with chinese label doesn't not work.