$Ast = {
    Set-Alias -Name Test -Value SomeValue
    New-Alias -Name SomeOtherAlias -Value SomeValue
}.Ast
$SetAliasCommands = $Ast.FindAll({$args[0] -is [System.Management.Automation.Language.CommandAst] -and ($Command.CommandElements[0].Value -eq 'Set-Alias' -or $Command.CommandElements[0].Value -eq 'New-Alias')}, $true)

foreach($SetAliasCommand in $SetAliasCommands)
{
    $NextElementIsNameValue = $false

    foreach($element in $SetAliasCommand.CommandElements)
    {
        if ($NextElementIsNameValue)
        {
            $element.Value
            break
        }

        if ($element -is [System.Management.Automation.Language.CommandParameterAst] -and $element.ParameterName -eq 'Name')
        {
            $NextElementIsNameValue = $true
        }
    }
}