Shell integration with PowerShell 5.1 breaks with `$ErrorActionPreference = 'stop'`

[andyleejordan]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.81.0
• OS Version: Windows_NT x64 10.0.19045

Steps to Reproduce:

In $PROFILE.CurrentUserAllHosts, set the content to

$ErrorActionPreference = 'stop'
Set-StrictMode -Version Latest

then start VS Code with shell integration enabled and use Windows PowerShell.

This bug will occur: PowerShell/PowerShellEditorServices#2050

The use of $IsWindows at:

vscode/src/vs/workbench/contrib/terminal/browser/media/shellIntegration.ps1

Line 123 in 8429ea9

[Console]::Write("$([char]0x1b)]633;P;IsWindows=$($IsWindows)`a")

Needs to be guarded for Windows PowerShell (where it doesn't exist).

/cc @Tyriar

[andyleejordan]

Sharing from my profile:

if ($PSVersionTable.PSVersion -lt "6.0") {
  $global:IsWindows = $true
}