Update build-windows-toolchain.bat

Author: compnerd

utils/build-windows-toolchain.bat

@@ -819,6 +819,8 @@ endlocal
 :FetchX64Toolchain
 setlocal enableextensions enabledelayedexpansion
 
+dotnet tool list -g | findstr wix
+IF NOT %ERRORLEVEL% EQU 0 DO ( dotnet tool install -g wix || (exit /b) )
 curl.exe -sOL "https://download.swift.org/development/windows10/swift-DEVELOPMENT-SNAPSHOT-2023-08-12-a/swift-DEVELOPMENT-SNAPSHOT-2023-08-12-a-windows10.exe" || (exit /b)
 "%UserProfile%\.nuget\packages\wix\4.0.1\tools\net6.0\any\wix.exe" burn extract swift-DEVELOPMENT-SNAPSHOT-2023-08-12-a-windows10.exe -o "%BuildRoot%\toolchains" || (exit /b)
 msiexec.exe /qn /a "%BuildRoot%\toolchains\a0" TARGETDIR="%BuildRoot%\toolchains\swift-DEVELOPMENT-SNAPSHOT-2023-08-12-a\PFiles64\Swift\Runtimes\0.0.0\usr\bin\  || (exit /b)