ci: Add script to repackage IAR toolchains for Windows

IAR toolchains for Windows are provided only via installer executables.
Add a script to repackage the parts we need for CMake's CI jobs.

.gitlab/ci/repackage/iar.ps1

@@ -0,0 +1,38 @@
+# IAR Tooling for Windows is available only via installers.
+# Run an installer and repackage the installation directory.
+
+#Requires -RunAsAdministrator
+
+param (
+  [Parameter(Mandatory=$true)]
+  [string]$installer,
+  [string]$revision = "1",
+  [string]$basedir = "c:\iar"
+  )
+
+$erroractionpreference = "stop"
+
+Add-Type -AssemblyName System.IO.Compression.FileSystem
+
+$installer_file = Get-Item $installer
+$installer_name = $installer_file.Name
+$package_name = $installer_file.Basename + "-" + $revision
+$package_dir = "$basedir\$package_name"
+
+
+Write-Host "Installing to: $package_dir"
+Start-Process -Wait -FilePath "$installer_file" -ArgumentList "/hide_usd /autoinstall/$package_dir"
+@"
+This was repackaged from an installation by "$installer_name".
+Obtain a network license as follows:
+
+  set IAR_LMS_SETTINGS_DIR=%cd%\license
+  %cd%\common\bin\lightlicensemanager setup --host %LicenseServerHostname%
+
+"@ | Add-Content -NoNewline "$package_dir/README.txt"
+
+
+Write-Host "Repackaging to: $package_name.zip"
+$compressionLevel = [System.IO.Compression.CompressionLevel]::Optimal
+$includeBaseDirectory = $true
+[System.IO.Compression.ZipFile]::CreateFromDirectory("$package_dir", "$package_name.zip", $compressionLevel, $includeBaseDirectory)