Merge 'release/2.1' into merge/release/2.1-to-release/2.2

Ignore submodule and ProdCon updates: 2.2 is newer.

The dotnet/standard submodule update to 2.0.3 is applicable to the 2.2 branch at this point in time, but another PR will update it to an even newer version so the change is being excluded here.

Author: dagood

dir.props

@@ -46,7 +46,7 @@
     <ToolPackageExtractDir>$(ToolsDir)source-built/</ToolPackageExtractDir>
     <ToolsLocalDir>$(ProjectDir)tools-local/</ToolsLocalDir>
     <TaskDirectory>$(ToolsLocalDir)tasks/</TaskDirectory>
-    <TasksBinDir>$(TaskDirectory)Microsoft.DotNet.SourceBuild.Tasks/bin/Debug/netstandard2.0/</TasksBinDir>
+    <TasksBinDir>$(TaskDirectory)Microsoft.DotNet.SourceBuild.Tasks/bin/Debug/netstandard1.5/</TasksBinDir>
     <BaseIntermediatePath>$(BaseOutputPath)obj/</BaseIntermediatePath>
     <OutputPath>$(BaseOutputPath)$(Platform)/$(Configuration)/</OutputPath>
     <IntermediatePath>$(BaseIntermediatePath)$(Platform)/$(Configuration)/</IntermediatePath>

tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks/Microsoft.DotNet.SourceBuild.Tasks.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))/dir.props" />
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>netstandard1.5</TargetFramework>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <CoreSetupPlatformAbstractionsPath>$(SubmoduleDirectory)core-setup/src/managed/Microsoft.DotNet.PlatformAbstractions/</CoreSetupPlatformAbstractionsPath>
     <OutputPath>$(MSBuildThisFileDirectory)bin/$(Configuration)</OutputPath>
@@ -27,6 +27,9 @@
     <PackageReference Include="Microsoft.Build.Utilities.Core">
       <Version>15.6.82</Version>
     </PackageReference>
+    <PackageReference Include="System.ValueTuple">
+      <Version>4.4.0</Version>
+    </PackageReference>
   </ItemGroup>
 
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