Move default RuntimeIdentifiers for cross-targeting to BeforeCommon

This resolves conflict with Microsoft.NuGet.targets imported on full
framework MSBuild. Work is in progress to remove that import, but this
decouples that from the change to allow desktop exe projects without
explicit RID.

Author: nguerrera

src/Tasks/Microsoft.NET.Build.Tasks/build/Microsoft.NET.Sdk.BeforeCommonCrossTargeting.targets

@@ -11,6 +11,19 @@ Copyright (c) .NET Foundation. All rights reserved.
 -->
 <Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
+  <!-- 
+    Nuget doesn't see or use runtime identifiers in restore that are only
+    conditionally used in some inner builds.
+    
+    However, in the case where we're building .NETFramework exe on Windows 
+    (see *.RuntimeIdentifierInference.targets for more information) in an inner
+    build, we may implicitly use one of these RIDs and so we must ensure that restore
+    includes them.
+  -->
+  <PropertyGroup Condition="'$(RuntimeIdentifiers)' == '' and '$(OS)' == 'Windows_NT'">
+    <RuntimeIdentifiers>win7-x86;win7-x64</RuntimeIdentifiers>
+  </PropertyGroup>
+
   <Import Project="$(MSBuildThisFileDirectory)Microsoft.NET.DefaultAssemblyInfo.targets" />
   <Import Project="$(MSBuildThisFileDirectory)Microsoft.NET.DefaultOutputPaths.targets" />
 

src/Tasks/Microsoft.NET.Build.Tasks/buildCrossTargeting/Microsoft.NET.Sdk.targets

@@ -30,17 +30,5 @@ Copyright (c) .NET Foundation. All rights reserved.
   <Target Name="Publish">
     <Error Text="The 'Publish' target is not supported without specifying a target framework. The current project targets multiple frameworks, please specify the framework for the published application." />
   </Target>
-  
-  <!-- 
-    Nuget doesn't see or use runtime identifiers in restore that are only
-    conditionally used in some inner builds. 
-    
-    However, in the case where we're building .NETFramework exe on Windows 
-    (see *.RuntimeIdentifierInference.targets for more information) in an inner
-    build, we may implicitly use one of these RIDs and so we must ensure that restore 
-    includes them.
-   -->
-  <PropertyGroup Condition="'$(RuntimeIdentifiers)' == '' and '$(OS)' == 'Windows_NT'">
-    <RuntimeIdentifiers>win7-x86;win7-x64</RuntimeIdentifiers>
-  </PropertyGroup>
+
 </Project>