WiX: prepare the toolchain MSIs for ARM64

Introduce the ability to have more than one architecture for the
devtools and toolchain components.  This is in preparation for
introducing the ability to package up the toolchain for the ARM64 host.

Author: compnerd

platforms/Windows/devtools.wxs renamed to platforms/Windows/devtools-amd64.wxs

@@ -8,6 +8,9 @@
   </PropertyGroup>
 
   <PropertyGroup>
+    <ProductArchitecture Condition=" '$(ProductArchitecture)' == '' ">amd64</ProductArchitecture>
+    <ProductArchitecture>$(ProductArchitecture)</ProductArchitecture>
+
     <ProductVersion Condition=" '$(ProductVersion)' == '' ">0.0.0</ProductVersion>
     <ProductVersion>0.0.0</ProductVersion>
   </PropertyGroup>
@@ -36,6 +39,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="devtools.wxs" />
+    <Compile Include="devtools-$(ProductArchitecture).wxs" />
   </ItemGroup>
 </Project>

platforms/Windows/devtools.wixproj

@@ -5,6 +5,12 @@
     <OutputType>Package</OutputType>
     <ProjectGuid>6ebfb883-fc92-4b73-81ae-ddeb2cec4df9</ProjectGuid>
     <SchemaVersion>2.0</SchemaVersion>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <ProductArchitecture Condition=" '$(ProductArchitecture)' == '' ">amd64</ProductArchitecture>
+    <ProductArchitecture>$(ProductArchitecture)</ProductArchitecture>
+
     <ProductVersion Condition=" '$(ProductVersion)' == '' ">0.0.0</ProductVersion>
     <ProductVersion>$(ProductVersion)</ProductVersion>
   </PropertyGroup>
@@ -49,6 +55,6 @@
   </Target>
 
   <ItemGroup>
-    <Compile Include="toolchain.wxs" />
+    <Compile Include="toolchain-$(ProductArchitecture).wxs" />
   </ItemGroup>
 </Project>