Import illink.targets for ref projects (#118144)

This lets the logic from the ILLink targets add
`AssemblyMetadata("IsTrimmable", "true")` to ref projects which have
trimming enabled.

Also moves the trimming opt-out into `Directory.Build.props` when it
should be shared between src and corresponding ref projects.

This will be used to enable the Roslyn analyzer to produce a warning
for references to assemblies that aren't marked "IsTrimmable".

Author: sbomer

src/libraries/Directory.Build.targets

@@ -135,7 +135,7 @@
   <Import Project="$(RepositoryEngineeringDir)testing\runsettings.targets" Condition="'$(EnableRunSettingsSupport)' == 'true'" />
   <Import Project="$(RepositoryEngineeringDir)testing\coverage.targets" Condition="'$(EnableRunSettingsSupport)' == 'true' or '$(EnableCoverageSupport)' == 'true'" />
 
-  <Import Project="$(RepositoryEngineeringDir)illink.targets" Condition="'$(IsSourceProject)' == 'true' or '$(ExplicitlyImportCustomILLinkTargets)' == 'true'" />
+  <Import Project="$(RepositoryEngineeringDir)illink.targets" Condition="'$(IsSourceProject)' == 'true' or '$(IsReferenceAssemblyProject)' == 'true' or '$(ExplicitlyImportCustomILLinkTargets)' == 'true'" />
   <Import Project="$(RepositoryEngineeringDir)liveILLink.targets" />
   <Import Project="$(RepositoryEngineeringDir)nativeSanitizers.targets" />
 

src/libraries/System.CodeDom/Directory.Build.props

@@ -3,5 +3,6 @@
   <PropertyGroup>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
     <UnsupportedOSPlatforms>browser;wasi;ios;tvos;maccatalyst</UnsupportedOSPlatforms>
+    <IsTrimmable>false</IsTrimmable>
   </PropertyGroup>
 </Project>

src/libraries/System.CodeDom/src/System.CodeDom.csproj

@@ -3,7 +3,6 @@
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);CODEDOM</DefineConstants>
-    <IsTrimmable>false</IsTrimmable>
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
     <IsPackable>true</IsPackable>
     <PackageDescription>Provides types that can be used to model the structure of a source code document and to output source code for that model in C# or Visual Basic.</PackageDescription>

src/libraries/System.ComponentModel.Composition.Registration/Directory.Build.props

@@ -2,5 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>ECMA</StrongNameKeyId>
+    <IsTrimmable>false</IsTrimmable>
   </PropertyGroup>
 </Project>

src/libraries/System.ComponentModel.Composition.Registration/src/System.ComponentModel.Composition.Registration.csproj

@@ -2,7 +2,6 @@
 
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.1</TargetFrameworks>
-    <IsTrimmable>false</IsTrimmable>
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
     <IsPackable>true</IsPackable>
     <AddNETFrameworkPlaceholderFileToPackage>true</AddNETFrameworkPlaceholderFileToPackage>

src/libraries/System.ComponentModel.Composition/Directory.Build.props

@@ -2,5 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>ECMA</StrongNameKeyId>
+    <IsTrimmable>false</IsTrimmable>
   </PropertyGroup>
 </Project>

src/libraries/System.ComponentModel.Composition/src/System.ComponentModel.Composition.csproj

@@ -2,7 +2,6 @@
 
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.0</TargetFrameworks>
-    <IsTrimmable>false</IsTrimmable>
     <EnableAOTAnalyzer>false</EnableAOTAnalyzer>
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
     <IsPackable>true</IsPackable>

src/libraries/System.Configuration.ConfigurationManager/Directory.Build.props

@@ -3,5 +3,7 @@
   <PropertyGroup>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
     <UnsupportedOSPlatforms>browser;wasi</UnsupportedOSPlatforms>
+    <!-- opt-out of trimming until it works https://github.com/dotnet/runtime/issues/49062 -->
+    <IsTrimmable>false</IsTrimmable>
   </PropertyGroup>
 </Project>

src/libraries/System.Configuration.ConfigurationManager/src/System.Configuration.ConfigurationManager.csproj

@@ -3,8 +3,6 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <NoWarn>$(NoWarn);CA2249</NoWarn>
-    <!-- opt-out of trimming until it works https://github.com/dotnet/runtime/issues/49062 -->
-    <IsTrimmable>false</IsTrimmable>
     <EnableAOTAnalyzer>false</EnableAOTAnalyzer>
     <IncludeInternalObsoleteAttribute>true</IncludeInternalObsoleteAttribute>
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>

src/libraries/System.Speech/Directory.Build.props

@@ -3,5 +3,6 @@
   <PropertyGroup>
     <StrongNameKeyId>MicrosoftShared</StrongNameKeyId>
     <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <IsTrimmable>false</IsTrimmable>
   </PropertyGroup>
 </Project>