Cmdlets that run in current scope (like ForEach-Object) not accounted for by PSUseDeclaredVarsMoreThanAssignments

Although issue #1031 and #1129 probably have the same cause, I have added a new bug report as it is (afaik) not directly related to the Begin, Process and End function blocks as suggested in there which brings the issue in a different perspective.

Apparently for some cmdlets, PowerShell is invoked in the current scope but that is apparently not respected by the PSScriptAnalyzer.

Steps to reproduce

$Test = $False
1..3 | ForEach-Object {$Test = $True}
$Test

note that the result of the above is $True, meaning that the value of $Test is actually assigned and changed to $True within the ForEach-Object cmdlet.

Expected behavior

No warning.

Actual behavior

RuleName                            Severity     ScriptName Line  Message
--------                            --------     ---------- ----  -------
PSUseDeclaredVarsMoreThanAssignment Warning      Test.ps1   2     The variable 'Test' is assigned but never used.

Environment data

Name                           Value
----                           -----
PSVersion                      5.1.17134.590
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.17134.590
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

PSScriptAnalyzer.Version:    1.17.1

Will this eventually be resolved?
How can I nicely avoid the incorrect warning in an example like above?

Start by running the PowerShell reproduction with PSUseDeclaredVarsMoreThanAssignments and confirm the warning for the ForEach-Object assignment. Trace the rule's handling of current-scope cmdlets, and consider the issue done when the example produces no warning without regressing ordinary unused-assignment diagnostics.