build: adjust the paths for the runtime MSI packaging rules

This is the build rules update to match
swiftlang/swift-installer-scripts#224.

Author: compnerd

utils/build-windows-toolchain.bat

@@ -978,11 +978,11 @@ msbuild %SourceRoot%\swift-installer-scripts\platforms\Windows\sdk\sdk.wixproj ^
 :: TODO(compnerd) actually perform the code-signing
 :: signtool sign /f Apple_CodeSign.pfx /p Apple_CodeSign_Password /tr http://timestamp.digicert.com /fd sha256 %PackageRoot%\sdk\sdk.msi
 
-:: Package runtime.msi
-msbuild %SourceRoot%\swift-installer-scripts\platforms\Windows\runtimemsi\runtimemsi.wixproj ^
+:: Package rtl.msi
+msbuild %SourceRoot%\swift-installer-scripts\platforms\Windows\rtl\msi\rtlmsi.wixproj ^
   -restore ^
   -p:Configuration=Release ^
-  -p:BaseOutputPath=%PackageRoot%\runtime\ ^
+  -p:BaseOutputPath=%PackageRoot%\rtl\ ^
   -p:SDK_ROOT=%SDKInstallRoot%\
 :: TODO(compnerd) actually perform the code-signing
 :: signtool sign /f Apple_CodeSign.pfx /p Apple_CodeSign_Password /tr http://timestamp.digicert.com /fd sha256 %PackageRoot%\runtime\runtime.msi
@@ -993,7 +993,7 @@ move %PackageRoot%\cli\Release\amd64\cli.msi %PackageRoot% || (exit /b)
 move %PackageRoot%\dbg\Release\amd64\dbg.msi %PackageRoot% || (exit /b)
 move %PackageRoot%\ide\Release\amd64\ide.msi %PackageRoot% || (exit /b)
 move %PackageRoot%\sdk\Release\amd64\sdk.msi %PackageRoot% || (exit /b)
-move %PackageRoot%\runtime\Release\amd64\runtime.msi %PackageRoot% || (exit /b)
+move %PackageRoot%\rtl\Release\amd64\rtl.msi %PackageRoot% || (exit /b)
 
 :: Build Installer
 msbuild %SourceRoot%\swift-installer-scripts\platforms\Windows\bundle\installer.wixproj ^