Implement cpobj opcode for wasm (#5151)

* Implement cpobj opcode for wasm

Implements the ILToWebAssembly.ImportCpObj method using an LLVM load and
store.

Adds a test for for wasm cpobj to the HelloWasm test using an IL
project.

4 files changed, 66 insertions, 0 deletions

diff --git a/tests/src/Simple/HelloWasm/CpObj.il b/tests/src/Simple/HelloWasm/CpObj.il
new file mode 100644
index 000000000..ca6444dee
--- /dev/null
+++ b/tests/src/Simple/HelloWasm/CpObj.il
@@ -0,0 +1,34 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+.assembly extern mscorlib
+{
+  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )
+  .ver 4:0:0:0
+}
+
+.assembly extern System.Private.CoreLib
+{
+  .publickeytoken = (B0 3F 5F 7F 11 D5 0A 3A )
+  .ver 4:0:0:0
+}
+
+.assembly CpObj { }
+
+.class public CpObj.CpObjTest
+{
+  .method public hidebysig static void CpObj(valuetype CpObj.TestValue& dest, valuetype CpObj.TestValue& src) cil managed
+  {
+    .maxstack 8
+    ldarg.0
+    ldarg.1
+    cpobj CpObj.TestValue
+    ret
+  }
+}
+
+.class public value sealed CpObj.TestValue
+{
+  .field public int32 Field;
+}
\ No newline at end of file
diff --git a/tests/src/Simple/HelloWasm/CpObj.ilproj b/tests/src/Simple/HelloWasm/CpObj.ilproj
new file mode 100644
index 000000000..e21390e95
--- /dev/null
+++ b/tests/src/Simple/HelloWasm/CpObj.ilproj
@@ -0,0 +1,20 @@
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <OutputType>Library</OutputType>
+    <DebugType>portable</DebugType>
+    <OutputPath>$(MSBuildProjectDirectory)\bin\$(Configuration)\$(Platform)\</OutputPath>
+    <IntermediateOutputPath>$(MSBuildProjectDirectory)\obj\$(Configuration)\$(Platform)\</IntermediateOutputPath>
+  </PropertyGroup>
+
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+
+  <ItemGroup>
+    <Compile Include="CpObj.il" />
+    <PackageReference Include="Microsoft.NETCore.App">
+      <Version>$(MicrosoftNETCoreAppPackageVersion)</Version>
+    </PackageReference>
+  </ItemGroup>
+  
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
diff --git a/tests/src/Simple/HelloWasm/HelloWasm.csproj b/tests/src/Simple/HelloWasm/HelloWasm.csproj
index 45ebce05d..b767a5dbd 100644
--- a/tests/src/Simple/HelloWasm/HelloWasm.csproj
+++ b/tests/src/Simple/HelloWasm/HelloWasm.csproj
@@ -1,6 +1,9 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
     <Compile Include="*.cs" />
+
+    <ProjectReference Include="CpObj.ilproj" />
+    <IlcArg Include="-r:$(IntermediateOutputPath)\CpObj.dll" />
   </ItemGroup>
 
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), SimpleTest.targets))\SimpleTest.targets" />
diff --git a/tests/src/Simple/HelloWasm/Program.cs b/tests/src/Simple/HelloWasm/Program.cs
index 145694210..25886330c 100644
--- a/tests/src/Simple/HelloWasm/Program.cs
+++ b/tests/src/Simple/HelloWasm/Program.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Runtime.InteropServices;
+using CpObj;
 
 internal static class Program
 {
@@ -108,6 +109,14 @@ internal static class Program
         {
             PrintLine("SwitchOpDefault test: Ok.");
         }
+
+        var cpObjTestA = new TestValue { Field = 1234 };
+        var cpObjTestB = new TestValue { Field = 5678 };
+        CpObjTest.CpObj(ref cpObjTestB, ref cpObjTestA);
+        if (cpObjTestB.Field == 1234)
+        {
+            PrintLine("CpObj test: Ok.");
+        }
     }
 
     private static unsafe void PrintString(string s)