PSScriptAnalyzer incorrectly flags a variable as assigned but never used

[krissmilne]

System Details

• Windows 10 1511
• VS Code Version: 1.14.2
• PowerShell extension version: 1.4.1
• $PSVersionTable

---

PSVersion 5.0.10586.962
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.10586.962
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1

---

Issue Description

When a variable is declared either in the begin block or statement block of a ForEach-Object pipeline, the PSScriptAnalyzer incorrectly flags it as assigned but never used.

Examples:
$Count is incorreclty flagged as assigned but never used
$myArray = @()
$myArray += "Item1"
$myArray += "Item2"
$myArray += "Item3"
$myArray += "Item4"
$myArray | ForEach-Object {$Count = 0} {$Count++; $Count}

[daviwil]

This is covered by PowerShell/PSScriptAnalyzer#711, will close this issue in favor of that one.