Net Standard 2.0 only FSharp.Core (dotnet#9801)

* Net standard only FSharp.Core

* temp

Author: KevinRansom

VisualFSharp.sln

@@ -139,6 +139,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NuGet", "NuGet", "{647810D0-5307-448F-99A2-E83917010DAE}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.FSharp.Compiler", "src\fsharp\Microsoft.FSharp.Compiler\Microsoft.FSharp.Compiler.csproj", "{04C59F6E-1C76-4F6A-AC21-2EA7F296A1B8}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.FSharp.Compiler", "src\fsharp\FSharp.Compiler.nuget\Microsoft.FSharp.Compiler.csproj", "{04C59F6E-1C76-4F6A-AC21-2EA7F296A1B8}"
 EndProject
 Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "FSharp.Compiler.Private.Scripting", "src\fsharp\FSharp.Compiler.Private.Scripting\FSharp.Compiler.Private.Scripting.fsproj", "{20B7BC36-CF51-4D75-9E13-66681C07977F}"
 EndProject

eng/Build.ps1

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information. -->
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <!-- When compiling .NET SDK 2.0 projects targeting .NET 4.x on Mono using 'dotnet build' you -->
+    <!-- have to teach MSBuild where the Mono copy of the reference asssemblies is -->
+    <TargetIsMono Condition="$(TargetFramework.StartsWith('net4')) and '$(OS)' == 'Unix'">true</TargetIsMono>
+    
+    <!-- Look in the standard install locations -->
+    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/Library/Frameworks/Mono.framework/Versions/Current/lib/mono')">/Library/Frameworks/Mono.framework/Versions/Current/lib/mono</BaseFrameworkPathOverrideForMono>
+    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/usr/lib/mono')">/usr/lib/mono</BaseFrameworkPathOverrideForMono>
+    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/usr/local/lib/mono')">/usr/local/lib/mono</BaseFrameworkPathOverrideForMono>
+
+    <!-- If we found Mono reference assemblies, then use them -->
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net45'">$(BaseFrameworkPathOverrideForMono)/4.5-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net451'">$(BaseFrameworkPathOverrideForMono)/4.5.1-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net452'">$(BaseFrameworkPathOverrideForMono)/4.5.2-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net46'">$(BaseFrameworkPathOverrideForMono)/4.6-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net461'">$(BaseFrameworkPathOverrideForMono)/4.6.1-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net462'">$(BaseFrameworkPathOverrideForMono)/4.6.2-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net47'">$(BaseFrameworkPathOverrideForMono)/4.7-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net471'">$(BaseFrameworkPathOverrideForMono)/4.7.1-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net472'">$(BaseFrameworkPathOverrideForMono)/4.7.2-api</FrameworkPathOverride>
+    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND '$(TargetFramework)' == 'net48'">$(BaseFrameworkPathOverrideForMono)/4.8-api</FrameworkPathOverride>
+    <EnableFrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != ''">true</EnableFrameworkPathOverride>
+
+    <!-- Add the Facades directory.  Not sure how else to do this. Necessary at least for .NET 4.5 -->
+    <AssemblySearchPaths Condition="'$(BaseFrameworkPathOverrideForMono)' != ''">$(FrameworkPathOverride)/Facades;$(AssemblySearchPaths)</AssemblySearchPaths>
+  </PropertyGroup>
+</Project>

fcs/FSharp.Compiler.Service/FSharp.Compiler.Service.fsproj

@@ -100,6 +100,8 @@ folder "InstallDir:Common7\IDE\CommonExtensions\Microsoft\FSharp"
   file source="$(BinariesFolder)\FSharp.Compiler.Server.Shared\$(Configuration)\$(TargetFramework)\FSharp.Compiler.Server.Shared.dll" vs.file.ngen=yes vs.file.ngenArchitecture=All vs.file.ngenPriority=2
   file source="$(BinariesFolder)\FSharp.Core\$(Configuration)\netstandard2.0\FSharp.Core.dll" vs.file.ngen=yes vs.file.ngenArchitecture=All vs.file.ngenPriority=2
   file source="$(BinariesFolder)\FSharp.Core\$(Configuration)\netstandard2.0\FSharp.Core.xml"
+  file source="$(BinariesFolder)\FSharp.Core\$(Configuration)\netstandard2.0\FSharp.Core.optdata"
+  file source="$(BinariesFolder)\FSharp.Core\$(Configuration)\netstandard2.0\FSharp.Core.sigdata"
   file source="$(BinariesFolder)\FSharp.Build\$(Configuration)\$(TargetFramework)\FSharp.Build.dll" vs.file.ngen=yes vs.file.ngenArchitecture=All vs.file.ngenPriority=2
   file source="$(BinariesFolder)\Microsoft.DotNet.DependencyManager\$(Configuration)\net472\Microsoft.DotNet.DependencyManager.dll" vs.file.ngen=yes vs.file.ngenArchitecture=All vs.file.ngenPriority=2
   file source="$(BinariesFolder)\FSharp.Build\$(Configuration)\$(TargetFramework)\Microsoft.Build.Framework.dll"