Description

Because of this issue, it's not possible to provide completion for native command parameters.

Inputs that repro the issue for command 'foo' (i.e. do not invoke completion):

1. foo -<tab>
2. foo -a<tab>
3. foo --<tab>

Inputs that do not repro the issue:

1. foo --a<tab>
2. foo ---<tab>

The issue repros with and without PSReadLine.

Steps to reproduce

1. Register a new argument completer
   Register-ArgumentCompleter -Native -CommandName foo -ScriptBlock { "bar" }

2. Type 'foo -<tab>'

Expected behavior

'foo -' completes to 'foo bar'

Actual behavior

The text does not change

Environment data

> $PSVersionTable

Name                           Value
----                           -----
PSRemotingProtocolVersion      2.3
CLRVersion
WSManStackVersion              3.0
SerializationVersion           1.1.0.1
GitCommitId                    v6.0.0-alpha.14
PSVersion                      6.0.0-alpha
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSEdition                      Core
BuildVersion                   3.0.0.0