[tools] Convenience tool for loading MSVC envirroment

tools/windows/load-msvc-env.ps1

@@ -0,0 +1,42 @@
+# SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+$osArch = [System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture
+
+switch ($osArch) {
+    "X64"   { $arch = "x64" }
+    "Arm64" { $arch = "arm64" }
+    default {
+        Write-Error "❌ Unsupported architecture: $osArch"
+        exit 1
+    }
+}
+
+$vswhere = "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe"
+
+if (!(Test-Path $vswhere)) {
+    Write-Error "load-msvc-env.ps1: vswhere not found"
+    exit 1
+}
+
+$vs = & $vswhere -latest -products * -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath
+
+if (-not $vs) {
+    Write-Error "load-msvc-env.ps1: Visual Studio (with Desktop development with C++) not found"
+    exit 1
+}
+
+$bat = "$vs\VC\Auxiliary\Build\vcvarsall.bat"
+
+if (!(Test-Path $bat)) {
+    Write-Error "load-msvc-env.ps1: (vcvarsall.bat) not found"
+    exit 1
+}
+
+cmd /c "`"$bat`" $arch && set" | ForEach-Object {
+    if ($_ -match "^(.*?)=(.*)$") {
+        [Environment]::SetEnvironmentVariable($matches[1], $matches[2], 'Process')
+    }
+}
+
+Write-Host "load-msvc-env.ps1: MSVC environment loaded for $arch ($vs)"