Use shared corelib files for ValueTask's System\Runtime\CompilerServi…

…ces classes

Also makes several ValueTask-related structs readonly, and removes a superfluous method from the API.

src/System.Runtime/ref/System.Runtime.cs

@@ -6432,9 +6432,9 @@ public readonly partial struct ConfiguredValueTaskAwaitable<TResult>
     {
         private readonly object _dummy;
         public System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable<TResult>.ConfiguredValueTaskAwaiter GetAwaiter() { throw null; }
-        public partial struct ConfiguredValueTaskAwaiter : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
+        public readonly partial struct ConfiguredValueTaskAwaiter : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
         {
-            private object _dummy;
+            private readonly object _dummy;
             public bool IsCompleted { get { throw null; } }
             public TResult GetResult() { throw null; }
             public void OnCompleted(System.Action continuation) { }
@@ -6714,9 +6714,9 @@ public sealed partial class UnsafeValueTypeAttribute : System.Attribute
     {
         public UnsafeValueTypeAttribute() { }
     }
-    public partial struct ValueTaskAwaiter<TResult> : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
+    public readonly partial struct ValueTaskAwaiter<TResult> : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
     {
-        private object _dummy;
+        private readonly object _dummy;
         public bool IsCompleted { get { throw null; } }
         public TResult GetResult() { throw null; }
         public void OnCompleted(System.Action continuation) { }
@@ -7978,8 +7978,6 @@ public void SetObserved() { }
         public TResult Result { get { throw null; } }
         public System.Threading.Tasks.Task<TResult> AsTask() { throw null; }
         public System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable<TResult> ConfigureAwait(bool continueOnCapturedContext) { throw null; }
-        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
-        public static System.Runtime.CompilerServices.AsyncValueTaskMethodBuilder<TResult> CreateAsyncMethodBuilder() { throw null; }
         public override bool Equals(object obj) { throw null; }
         public bool Equals(System.Threading.Tasks.ValueTask<TResult> other) { throw null; }
         public System.Runtime.CompilerServices.ValueTaskAwaiter<TResult> GetAwaiter() { throw null; }

src/System.Threading.Tasks.Extensions/ref/System.Threading.Tasks.Extensions.cs

@@ -29,18 +29,18 @@ public readonly partial struct ConfiguredValueTaskAwaitable<TResult>
     {
         private readonly object _dummy;
         public System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable<TResult>.ConfiguredValueTaskAwaiter GetAwaiter() { throw null; }
-        public partial struct ConfiguredValueTaskAwaiter : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
+        public readonly partial struct ConfiguredValueTaskAwaiter : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
         {
-            private object _dummy;
+            private readonly object _dummy;
             public bool IsCompleted { get { throw null; } }
             public TResult GetResult() { throw null; }
             public void OnCompleted(System.Action continuation) { }
             public void UnsafeOnCompleted(System.Action continuation) { }
         }
     }
-    public partial struct ValueTaskAwaiter<TResult> : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
+    public readonly partial struct ValueTaskAwaiter<TResult> : System.Runtime.CompilerServices.ICriticalNotifyCompletion, System.Runtime.CompilerServices.INotifyCompletion
     {
-        private object _dummy;
+        private readonly object _dummy;
         public bool IsCompleted { get { throw null; } }
         public TResult GetResult() { throw null; }
         public void OnCompleted(System.Action continuation) { }
@@ -62,8 +62,6 @@ namespace System.Threading.Tasks
         public TResult Result { get { throw null; } }
         public System.Threading.Tasks.Task<TResult> AsTask() { throw null; }
         public System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable<TResult> ConfigureAwait(bool continueOnCapturedContext) { throw null; }
-        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
-        public static System.Runtime.CompilerServices.AsyncValueTaskMethodBuilder<TResult> CreateAsyncMethodBuilder() { throw null; }
         public override bool Equals(object obj) { throw null; }
         public bool Equals(System.Threading.Tasks.ValueTask<TResult> other) { throw null; }
         public System.Runtime.CompilerServices.ValueTaskAwaiter<TResult> GetAwaiter() { throw null; }

src/System.Threading.Tasks.Extensions/src/System.Threading.Tasks.Extensions.csproj

@@ -23,11 +23,27 @@
     <ReferenceFromRuntime Include="System.Private.CoreLib" />
   </ItemGroup>
   <ItemGroup Condition="'$(IsPartialFacadeAssembly)' != 'true'">
-    <Compile Include="System\Runtime\CompilerServices\AsyncMethodBuilderAttribute.cs" />
-    <Compile Include="System\Runtime\CompilerServices\AsyncValueTaskMethodBuilder.cs" />
-    <Compile Include="System\Runtime\CompilerServices\ConfiguredValueTaskAwaitable.cs" />
-    <Compile Include="System\Runtime\CompilerServices\ValueTaskAwaiter.cs" />
-    <Compile Include="System\Threading\Tasks\ValueTask.cs" />
+    <Compile Include="System\Threading\Tasks\ValueTask.netstandard.cs" />
+
+    <Compile Include="$(CommonPath)\CoreLib\System\Diagnostics\StackTraceHiddenAttribute.cs">
+      <Link>Common\CoreLib\System\Diagnostics\StackTraceHiddenAttribute.cs</Link>
+    </Compile>
+    <Compile Include="$(CommonPath)\CoreLib\System\Runtime\CompilerServices\AsyncMethodBuilderAttribute.cs">
+      <Link>Common\CoreLib\System\Runtime\CompilerServices\AsyncMethodBuilderAttribute.cs</Link>
+    </Compile>
+    <Compile Include="$(CommonPath)\CoreLib\System\Runtime\CompilerServices\AsyncValueTaskMethodBuilder.cs">
+      <Link>Common\CoreLib\System\Runtime\CompilerServices\AsyncValueTaskMethodBuilder.cs</Link>
+    </Compile>
+    <Compile Include="$(CommonPath)\CoreLib\System\Runtime\CompilerServices\ConfiguredValueTaskAwaitable.cs">
+      <Link>Common\CoreLib\System\Runtime\CompilerServices\ConfiguredValueTaskAwaitable.cs</Link>
+    </Compile>
+    <Compile Include="$(CommonPath)\CoreLib\System\Runtime\CompilerServices\ValueTaskAwaiter.cs">
+      <Link>Common\CoreLib\System\Runtime\CompilerServices\ValueTaskAwaiter.cs</Link>
+    </Compile>
+    <Compile Include="$(CommonPath)\CoreLib\System\Threading\Tasks\ValueTask.cs">
+      <Link>Common\CoreLib\System\Threading\Tasks\ValueTask.cs</Link>
+    </Compile>
+
     <Reference Include="System.Collections" />
     <Reference Include="System.Diagnostics.Debug" />
     <Reference Include="System.Runtime" />