Revise based on C# LDM changes to model

Author: stephentoub

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -640,7 +640,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncIteratorMethodBuilder.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncIteratorStateMachineAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncMethodBuilderAttribute.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncMethodBuilderOverrideAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncMethodBuilderCore.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncStateMachineAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\CompilerServices\AsyncTaskMethodBuilder.cs" />

src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncMethodBuilderAttribute.cs

@@ -5,9 +5,10 @@ namespace System.Runtime.CompilerServices
 {
     /// <summary>
     /// Indicates the type of the async method builder that should be used by a language compiler to
-    /// build the attributed type when used as the return type of an async method.
+    /// build the attributed async method or to build the attributed type when used as the return type
+    /// of an async method.
     /// </summary>
-    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Interface | AttributeTargets.Delegate | AttributeTargets.Enum, Inherited = false, AllowMultiple = false)]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Interface | AttributeTargets.Delegate | AttributeTargets.Enum | AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
     public sealed class AsyncMethodBuilderAttribute : Attribute
     {
         /// <summary>Initializes the <see cref="AsyncMethodBuilderAttribute"/>.</summary>

src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncMethodBuilderOverrideAttribute.cs

@@ -9114,18 +9114,12 @@ public sealed partial class AsyncIteratorStateMachineAttribute : System.Runtime.
     {
         public AsyncIteratorStateMachineAttribute(System.Type stateMachineType) : base (default(System.Type)) { }
     }
-    [System.AttributeUsageAttribute(System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Interface | System.AttributeTargets.Struct, Inherited=false, AllowMultiple=false)]
+    [System.AttributeUsageAttribute(System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Interface | System.AttributeTargets.Method | System.AttributeTargets.Struct, Inherited=false, AllowMultiple=false)]
     public sealed partial class AsyncMethodBuilderAttribute : System.Attribute
     {
         public AsyncMethodBuilderAttribute(System.Type builderType) { }
         public System.Type BuilderType { get { throw null; } }
     }
-    [System.AttributeUsageAttribute(System.AttributeTargets.Class | System.AttributeTargets.Struct | System.AttributeTargets.Interface | System.AttributeTargets.Method | System.AttributeTargets.Constructor | System.AttributeTargets.Event | System.AttributeTargets.Property | System.AttributeTargets.Module, Inherited = false, AllowMultiple = true)]
-    public sealed partial class AsyncMethodBuilderOverrideAttribute : System.Attribute
-    {
-        public AsyncMethodBuilderOverrideAttribute(System.Type builderType) { }
-        public System.Type BuilderType { get { throw null; } }
-    }
     [System.AttributeUsageAttribute(System.AttributeTargets.Method, Inherited=false, AllowMultiple=false)]
     public sealed partial class AsyncStateMachineAttribute : System.Runtime.CompilerServices.StateMachineAttribute
     {

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

@@ -367,7 +367,7 @@ public static async Task NonGeneric_UsedWithAsyncMethod_CompletesSuccessfully(in
             await ValueTaskReturningAsyncMethod(84, result);
             Assert.Equal(84 + yields, result.Value);
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]
             async ValueTask ValueTaskReturningAsyncMethod(int result, StrongBox<int> output)
             {
                 for (int i = 0; i < yields; i++)
@@ -390,7 +390,7 @@ public static async Task Generic_UsedWithAsyncMethod_CompletesSuccessfully(int y
             Assert.Equal(42 + yields, await ValueTaskReturningAsyncMethod(42));
             Assert.Equal(84 + yields, await ValueTaskReturningAsyncMethod(84));
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
             async ValueTask<int> ValueTaskReturningAsyncMethod(int result)
             {
                 for (int i = 0; i < yields; i++)
@@ -412,7 +412,7 @@ public static async Task AwaitTasksAndValueTasks_InTaskAndValueTaskMethods()
                 Assert.Equal(18, await ValueTaskInt32ReturningMethod());
             }
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]
             async ValueTask ValueTaskReturningMethod()
             {
                 for (int i = 0; i < 3; i++)
@@ -440,7 +440,7 @@ async ValueTask ValueTaskReturningMethod()
                 }
             }
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
             async ValueTask<int> ValueTaskInt32ReturningMethod()
             {
                 for (int i = 0; i < 3; i++)
@@ -480,7 +480,7 @@ await Task.WhenAll(Enumerable.Range(0, Environment.ProcessorCount).Select(async
                 {
                     await ValueTaskAsync();
 
-                    [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder))]
+                    [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]
                     static async ValueTask ValueTaskAsync()
                     {
                         await Task.Delay(1);
@@ -499,7 +499,7 @@ await Task.WhenAll(Enumerable.Range(0, Environment.ProcessorCount).Select(async
                 {
                     Assert.Equal(42 + i, await ValueTaskAsync(i));
 
-                    [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
+                    [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
                     static async ValueTask<int> ValueTaskAsync(int i)
                     {
                         await Task.Delay(1);
@@ -549,14 +549,14 @@ public void PoolingAsyncValueTasksBuilder_ObjectsPooled(string limitEnvVar)
                 Assert.InRange(boxes.Distinct().Count(), 1, boxes.Count - 1);
             }, new RemoteInvokeOptions() { StartInfo = psi }).Dispose();
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder<int>))]
             static async ValueTask<int> ComputeAsync(int input, ConcurrentQueue<object> boxes)
             {
                 await RecursiveValueTaskAsync(3, boxes);
                 return input * 2;
             }
 
-            [AsyncMethodBuilderOverride(typeof(PoolingAsyncValueTaskMethodBuilder))]
+            [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]
             static async ValueTask RecursiveValueTaskAsync(int depth, ConcurrentQueue<object> boxes)
             {
                 boxes.Enqueue(await GetStateMachineData.FetchAsync());

src/libraries/System.Threading.Tasks.Extensions/tests/AsyncMethodBuilderOverrideAttributeTests.cs

@@ -6,7 +6,6 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="AsyncMethodBuilderAttributeTests.cs" />
-    <Compile Include="AsyncMethodBuilderOverrideAttributeTests.cs" />
     <Compile Include="AsyncValueTaskMethodBuilderTests.cs" />
     <Compile Include="ManualResetValueTaskSourceTests.cs" />
     <Compile Include="PoolingAsyncValueTaskMethodBuilderTests.cs" />