Fix ILLink.Substitutions.xml not being embedded in F# assemblies (#19124)

Author: Copilot

UseLocalCompiler.Directory.Build.props

@@ -18,6 +18,12 @@
     <FSharpPrefer64BitTools>True</FSharpPrefer64BitTools>
   </PropertyGroup>
 
+  <!-- 
+    Use FSharpTargetsShim to redirect the SDK to use the locally built F# targets.
+    This replaces all the individual UsingTask overrides since Microsoft.FSharp.NetSdk.targets
+    imports Microsoft.FSharp.Targets which registers all the F# build tasks.
+    See: https://github.com/dotnet/sdk/blob/main/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.FSharpTargetsShim.targets
+  -->
   <PropertyGroup Condition="'$(LoadLocalFSharpBuild)' == 'True'">
     <LocalFSharpBuildBinPath>$(LocalFSharpCompilerPath)/artifacts/bin/fsc/$(LocalFSharpCompilerConfiguration)/net10.0</LocalFSharpBuildBinPath>
     <FSharpBuildAssemblyFile>$(LocalFSharpBuildBinPath)/FSharp.Build.dll</FSharpBuildAssemblyFile>
@@ -27,9 +33,6 @@
     <FSharpOverridesTargetsShim>$(LocalFSharpBuildBinPath)/Microsoft.FSharp.Overrides.NetSdk.targets</FSharpOverridesTargetsShim>
   </PropertyGroup>
 
-  <UsingTask Condition="'$(LoadLocalFSharpBuild)' == 'True'" TaskName="FSharpEmbedResourceText" AssemblyFile="$(FSharpBuildAssemblyFile)" Override="true" />
-  <UsingTask Condition="'$(LoadLocalFSharpBuild)' == 'True'" TaskName="FSharpEmbedResXSource" AssemblyFile="$(FSharpBuildAssemblyFile)" Override="true" />
-
   <ItemGroup>
     <Reference Include="$(LocalFSharpCompilerPath)/artifacts/bin/FSharp.Core/$(LocalFSharpCompilerConfiguration)/netstandard2.0/FSharp.Core.dll" />
   </ItemGroup>

src/FSharp.Build/Microsoft.FSharp.NetSdk.targets

@@ -176,7 +176,7 @@ WARNING:  DO NOT MODIFY this file unless you are knowledgeable about MSBuild and
     <GenerateILLinkSubstitutions
       AssemblyName="$(AssemblyName)"
       IntermediateOutputPath="$(IntermediateOutputPath)">
-      <Output TaskParameter="GeneratedItems" ItemName="Embed" />
+      <Output TaskParameter="GeneratedItems" ItemName="EmbeddedResource" />
     </GenerateILLinkSubstitutions>
   </Target>
 

tests/AheadOfTime/Trimming/FSharpMetadataResource_Trimming_Test/FSharpMetadataResource_Trimming_Test.fsproj

@@ -22,17 +22,13 @@
     <Fsc_DotNET_DotnetFscCompilerPath>$(LocalFSharpBuildBinPath)/fsc.dll</Fsc_DotNET_DotnetFscCompilerPath>  
     <FSharpPreferNetFrameworkTools>False</FSharpPreferNetFrameworkTools>
     <FSharpPrefer64BitTools>True</FSharpPrefer64BitTools>
+    <!-- 
+      Use FSharpTargetsShim to redirect to the locally built targets file.
+      This is how the .NET SDK supports testing against local F# builds.
+      See https://github.com/dotnet/sdk/blob/main/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.FSharpTargetsShim.targets
+    -->
+    <FSharpTargetsShim>$(LocalFSharpBuildBinPath)/Microsoft.FSharp.NetSdk.targets</FSharpTargetsShim>
   </PropertyGroup>
-  
-  <UsingTask TaskName="GenerateILLinkSubstitutions" AssemblyFile="$(FSharpBuildAssemblyFile)" Override="true" />
-  
-  <Target Name="GenerateFSharpILLinkSubstitutions" BeforeTargets="AssignTargetPaths">
-    <GenerateILLinkSubstitutions
-      AssemblyName="$(AssemblyName)"
-      IntermediateOutputPath="$(IntermediateOutputPath)">
-      <Output TaskParameter="GeneratedItems" ItemName="EmbeddedResource" />
-    </GenerateILLinkSubstitutions>
-  </Target>
 
   <ItemGroup>
     <Compile Include="..\Program.fs" />