Handling enums as cmdlet parameters.

Summary of the new feature / enhancement

Changing the handling of enums as cmdlet parameters uses to display the possible values the values of the enum and the get the name for the value. Therefore xou get the same text if more than one name has the same value (see example below).

Proposed technical implementation details (optional)

<#
Display option when using an enum as a parameter of an CmdLet.
#>

Enum TestAction
{
Ignore = 0
Skip = 0
Replace = 1
New = 1
Remove = 2
Detete = 2

} # Enum TestAction

Function Test-Enum
{
param
(
[Parameter( Mandatory )]
[TestAction]
$Action
)
<#Do something#>

} # Function Test-Enum

<#
If you enter on a prompt
Test-Enum -Action
and try to select an action you get the following sequence:
Ignore
Ignore
Replace
Replace
Remove
Remove
Ignore
It would be nice to get the alias names as well.
Use [enum]::GetNames() instead [enum]::GetValues().
#>

从 issue #396 开始，使用重复的 enum 值复现 enum cmdlet 参数补全示例。调查当前获取 enum 值的参数补全入口点，然后验证补全会暴露每个名称，包括 Skip、New 和 Detete 等别名，且不会产生基于值的重复建议。