Ensure $(IntermediateOutputPath) exists, and include the right element after re-write

build/Targets/Imports.targets

@@ -318,9 +318,10 @@
   <Target Name="RewriteVsixManifestOnOfficialBuild"
           BeforeTargets="FindSourceVsixManifest"
           Condition="'$(IsDev15RC)' != 'true'">
+    <MakeDir Directories="$(IntermediateOutputPath)" />
     <XslTransformation XslInputPath="$(MSBuildThisFileDirectory)TransformVsixManifest.xslt"
                        XmlInputPaths="source.extension.vsixmanifest"
-                       OutputPaths="$(IntermediateOutputPath)source.extension.vsixmanifest" />
+                       OutputPaths="$(IntermediateOutputPath)\source.extension.vsixmanifest" />
     <ItemGroup>
       <!-- Note that `FindSourceVsixManifest` finds the first item in @None that matches the name.
            Our template projects include other manifests as content that are in @None, so make
@@ -328,7 +329,7 @@
       <None Remove="source.extension.vsixmanifest" />
       <_TempNoneForReordering Include="@(None)" />
       <None Remove="@(None)" />
-      <None Include="source.extension.vsixmanifest;@(_TempNoneForReordering)" />
+      <None Include="$(IntermediateOutputPath)\source.extension.vsixmanifest;@(_TempNoneForReordering)" />
     </ItemGroup>
   </Target>