Move a couple of WASM threading files to the shared partition (#118304)

* Move threading files

* Also move the WASI files for consistency

Author: SingleAccretion

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

@@ -2810,6 +2810,15 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\ThreadPool.Browser.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\TimerQueue.Browser.cs" />
   </ItemGroup>
+  <ItemGroup Condition="'$(TargetsWasi)' == 'true' and '$(FeatureWasmManagedThreads)' != 'true'">
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\ThreadPool.Wasi.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\TimerQueue.Wasi.cs" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetsBrowser)' == 'true' and '$(FeatureWasmManagedThreads)' == 'true'">
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\ThreadPoolBoundHandle.Browser.Threads.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\PortableThreadPool.Browser.Threads.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\ThreadPool.Browser.Threads.cs" />
+  </ItemGroup>
   <ItemGroup Condition="'$(FeatureObjCMarshal)' == 'true'">
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\InteropServices\ObjectiveC\ObjectiveCMarshal.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\InteropServices\ObjectiveC\ObjectiveCTrackedTypeAttribute.cs" />

src/mono/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Browser.Threads.Mono.cs renamed to src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Browser.Threads.cs

@@ -264,15 +264,6 @@
   <ItemGroup Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true') and '$(FeaturePortableThreadPool)' == 'true'">
       <Compile Include="$(BclSourcesRoot)\System\Threading\LowLevelLifoSemaphore.Unix.Mono.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsBrowser)' == 'true' and '$(FeatureWasmManagedThreads)' == 'true'">
-      <Compile Include="$(BclSourcesRoot)\System\Threading\ThreadPoolBoundHandle.Browser.Threads.Mono.cs" />
-      <Compile Include="$(BclSourcesRoot)\System\Threading\PortableThreadPool.Browser.Threads.Mono.cs" />
-      <Compile Include="$(BclSourcesRoot)\System\Threading\ThreadPool.Browser.Threads.Mono.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWasi)' == 'true'">
-      <Compile Include="$(BclSourcesRoot)\System\Threading\ThreadPool.Wasi.Mono.cs" />
-      <Compile Include="$(BclSourcesRoot)\System\Threading\TimerQueue.Wasi.Mono.cs" />
-  </ItemGroup>
   <ItemGroup>
       <Compile Include="$(BclSourcesRoot)\Mono\HotReload.cs" />
       <Compile Include="$(BclSourcesRoot)\Mono\RuntimeStructs.cs" />