Revert "Revert move of reference assemblies into obj" (#7075)

Reverts #6718

Fixes #6543. The blocking issues in other layers have been resolved.

documentation/wiki/ChangeWaves.md

@@ -31,6 +31,7 @@ A wave of features is set to "rotate out" (i.e. become standard functionality) t
 - [Scheduler should honor BuildParameters.DisableInprocNode](https://github.com/dotnet/msbuild/pull/6400)
 - [Don't compile globbing regexes on .NET Framework](https://github.com/dotnet/msbuild/pull/6632)
 - [Default to transitively copying content items](https://github.com/dotnet/msbuild/pull/6622)
+- [Reference assemblies are now no longer placed in the `bin` directory by default](https://github.com/dotnet/msbuild/pull/6560)
 - [Improve debugging experience: add global switch MSBuildDebugEngine; Inject binary logger from BuildManager; print static graph as .dot file](https://github.com/dotnet/msbuild/pull/6639)
 
 ## Change Waves No Longer In Rotation

src/Tasks/Microsoft.Common.CurrentVersion.targets

@@ -324,7 +324,8 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     <!-- Example, C:\MyProjects\MyProject\bin\Debug\MyAssembly.dll -->
     <TargetPath Condition=" '$(TargetPath)' == '' ">$(TargetDir)$(TargetFileName)</TargetPath>
 
-    <TargetRefPath Condition=" '$(TargetRefPath)' == '' and '$(ProduceReferenceAssembly)' == 'true' ">$([MSBuild]::NormalizePath($(TargetDir), 'ref', $(TargetFileName)))</TargetRefPath>
+    <TargetRefPath Condition=" '$(TargetRefPath)' == '' and '$(ProduceReferenceAssembly)' == 'true' and ('$(ProduceReferenceAssemblyInOutDir)' == 'true' or '$([MSBuild]::AreFeaturesEnabled(17.0))' != 'true' ) ">$([MSBuild]::NormalizePath($(TargetDir), 'ref', $(TargetFileName)))</TargetRefPath>
+    <TargetRefPath Condition=" '$(TargetRefPath)' == '' and '$(ProduceReferenceAssembly)' == 'true' ">$([MSBuild]::NormalizePath($(MSBuildProjectDirectory), $(IntermediateOutputPath), 'ref', $(TargetFileName)))</TargetRefPath>
 
     <!-- Example, C:\MyProjects\MyProject\ -->
     <ProjectDir Condition=" '$(ProjectDir)' == '' ">$([MSBuild]::EnsureTrailingSlash($(MSBuildProjectDirectory)))</ProjectDir>
@@ -393,9 +394,10 @@ Copyright (C) Microsoft Corporation. All rights reserved.
   </ItemGroup>
 
   <ItemGroup Condition="'$(ProduceReferenceAssembly)' == 'true'">
-    <IntermediateRefAssembly Include="$(IntermediateOutputPath)ref\$(TargetName)$(TargetExt)" Condition="'@(IntermediateRefAssembly)' == ''" />
+    <IntermediateRefAssembly Include="$(IntermediateOutputPath)refint\$(TargetName)$(TargetExt)" Condition="'@(IntermediateRefAssembly)' == ''" />
     <CreateDirectory Include="@(IntermediateRefAssembly->'%(RootDir)%(Directory)')" />
-    <CreateDirectory Include="$(OutDir)ref" />
+    <CreateDirectory Include="$(OutDir)ref" Condition=" '$(ProduceReferenceAssemblyInOutDir)' == 'true'" />
+    <CreateDirectory Include="$(IntermediateOutputPath)ref" Condition=" '$(ProduceReferenceAssemblyInOutDir)' != 'true'" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(_DebugSymbolsProduced)' == 'true'">