Compute ValInline.Never for externs (#15274)

* Compute ValInline.Never for externs

Author: vzarytovskii

src/Compiler/Checking/CheckExpressions.fs

@@ -2224,18 +2224,21 @@ module GeneralizationHelpers =
 //-------------------------------------------------------------------------
 
 let ComputeInlineFlag (memFlagsOption: SynMemberFlags option) isInline isMutable g attrs m =
-    let hasNoCompilerInliningAttribute() = HasFSharpAttribute g g.attrib_NoCompilerInliningAttribute attrs  
-    let isCtorOrAbstractSlot() =
+    let hasNoCompilerInliningAttribute () = HasFSharpAttribute g g.attrib_NoCompilerInliningAttribute attrs  
+
+    let isCtorOrAbstractSlot () =
         match memFlagsOption with
         | None -> false
         | Some x -> (x.MemberKind = SynMemberKind.Constructor) || x.IsDispatchSlot || x.IsOverrideOrExplicitImpl
 
+    let isExtern () = HasFSharpAttributeOpt g g.attrib_DllImportAttribute attrs
+
     let inlineFlag, reportIncorrectInlineKeywordUsage =
         // Mutable values may never be inlined
         // Constructors may never be inlined
         // Calls to virtual/abstract slots may never be inlined
         // Values marked with NoCompilerInliningAttribute or [<MethodImpl(MethodImplOptions.NoInlining)>] may never be inlined
-        if isMutable || isCtorOrAbstractSlot() || hasNoCompilerInliningAttribute() then
+        if isMutable || isCtorOrAbstractSlot() || hasNoCompilerInliningAttribute() || isExtern () then
             ValInline.Never, errorR
         elif HasMethodImplNoInliningAttribute g attrs then
             ValInline.Never, 

src/fsc/fsc.targets

@@ -40,8 +40,15 @@
     </NoneSubstituteText>
   </ItemGroup>
 
+    <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' != 'true'">
+    <ProjectReference Include="$(FSharpSourcesRoot)\FSharp.Core\FSharp.Core.fsproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' == 'true'">
+    <PackageReference Include="FSharp.Core" Version="$(FSharpCoreShippedPackageVersionValue)" />
+  </ItemGroup>
+
   <ItemGroup>
-    <ProjectReference Include="$(MSBuildThisFileDirectory)../FSharp.Core/FSharp.Core.fsproj" AdditionalProperties="TargetFramework=netstandard2.0" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)../FSharp.Build/FSharp.Build.fsproj" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)../Compiler/FSharp.Compiler.Service.fsproj" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)../FSharp.DependencyManager.Nuget/FSharp.DependencyManager.Nuget.fsproj" />

src/fsi/fsi.targets

@@ -45,8 +45,15 @@
     </NoneSubstituteText>
   </ItemGroup>
 
+  <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' != 'true'">
+    <ProjectReference Include="$(FSharpSourcesRoot)\FSharp.Core\FSharp.Core.fsproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' == 'true'">
+    <PackageReference Include="FSharp.Core" Version="$(FSharpCoreShippedPackageVersionValue)" />
+  </ItemGroup>
+
   <ItemGroup>
-    <ProjectReference Include="$(MSBuildThisFileDirectory)..\FSharp.Core\FSharp.Core.fsproj" AdditionalProperties="TargetFramework=netstandard2.0" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)..\Compiler\FSharp.Compiler.Service.fsproj" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)..\FSharp.Compiler.Interactive.Settings\FSharp.Compiler.Interactive.Settings.fsproj" />
   </ItemGroup>