Private field completions unexpectedly include insertText

[mjbvz]

From microsoft/vscode#88305

TypeScript Version: 3.8.0-dev.20200108

Search Terms:

• suggest / suggestion / suggestions
• completion / completions
• private fields
• completionInfo

Code
For the TS:

class K {
    #value: number;

    private keyword: number = 1;

    foo() {
       this.#va
    }
}

1. Trigger completions after #va

2. Accept suggestion for #value

Expected behavior:
The suggestion results in this.#value:

Actual behavior:

After the suggestion, there is an extra this.:

class Prv {
    #value: number;

    private keyword: number = 1;

    foo() {
        return this.this.#value;
    }
}

I believe the root cause is that insertText is being included for this completion item:

   {
            "name": "#value",
            "kind": "property",
            "kindModifiers": "",
            "sortText": "3",
            "insertText": "this.#value"
        },

Compare this with completions for private properties, which in a similar case do not include insertText:

        {
            "name": "keyword",
            "kind": "property",
            "kindModifiers": "private",
            "sortText": "0"
        },