C#: Initial NativeAOT support

This commit adds initial support for games exported as NativeAOT shared
libraries.

At this moment, the NativeAOT runtime is experimental. Additionally,
Godot is not trim-safe as it still makes some use of reflection.
For the time being, a rd.xml file is needed to prevent code triming:

```
<Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
  <Application>
    <Assembly Name="GodotSharp" Dynamic="Required All" />
    <Assembly Name="GAME_ASSEMBLY" Dynamic="Required All" />
  </Application>
</Directives>
```

These are the csproj changes for publishing:

```
  <PropertyGroup>
    <NativeLib>Shared</NativeLib>
  </PropertyGroup>
  <ItemGroup>
    <RdXmlFile Include="rd.xml" />
    <PackageReference Include="Microsoft.DotNet.ILCompiler" Version="7.0.0-*" />
  </ItemGroup>
```

More info:
- https://github.com/dotnet/runtimelab/blob/feature/NativeAOT/docs/using-nativeaot/compiling.md
- https://github.com/dotnet/runtimelab/tree/feature/NativeAOT/samples/NativeLibrary
- https://github.com/dotnet/runtimelab/blob/feature/NativeAOT/docs/using-nativeaot/rd-xml-format.md

3 files changed, 11 insertions, 6 deletions

diff --git a/modules/mono/editor/GodotTools/GodotTools/Build/BuildSystem.cs b/modules/mono/editor/GodotTools/GodotTools/Build/BuildSystem.cs
index 221deede2f..506c0ec067 100644
--- a/modules/mono/editor/GodotTools/GodotTools/Build/BuildSystem.cs
+++ b/modules/mono/editor/GodotTools/GodotTools/Build/BuildSystem.cs
@@ -197,10 +197,6 @@ namespace GodotTools.Build
             // Logger
             AddLoggerArgument(buildInfo, arguments);
 
-            // Trimming is not supported for dynamically loaded assemblies, as is our case with self hosting:
-            // https://github.com/dotnet/runtime/blob/main/docs/design/features/native-hosting.md#incompatible-with-trimming
-            arguments.Add("-p:PublishTrimmed=false");
-
             // Custom properties
             foreach (string customProperty in buildInfo.CustomProperties)
             {
diff --git a/modules/mono/editor/GodotTools/GodotTools/Export/ExportPlugin.cs b/modules/mono/editor/GodotTools/GodotTools/Export/ExportPlugin.cs
index edf3eeb7fa..8d88734ead 100644
--- a/modules/mono/editor/GodotTools/GodotTools/Export/ExportPlugin.cs
+++ b/modules/mono/editor/GodotTools/GodotTools/Export/ExportPlugin.cs
@@ -134,7 +134,16 @@ namespace GodotTools.Export
                 throw new Exception("Failed to build project");
             }
 
-            if (!File.Exists(Path.Combine(publishOutputTempDir, $"{GodotSharpEditor.ProjectAssemblyName}.dll")))
+            string soExt = ridOS switch
+            {
+                OS.DotNetOS.Win or OS.DotNetOS.Win10 => "dll",
+                OS.DotNetOS.OSX or OS.DotNetOS.iOS => "dylib",
+                _ => "so"
+            };
+
+            if (!File.Exists(Path.Combine(publishOutputTempDir, $"{GodotSharpEditor.ProjectAssemblyName}.dll"))
+                // NativeAOT shared library output
+                && !File.Exists(Path.Combine(publishOutputTempDir, $"{GodotSharpEditor.ProjectAssemblyName}.{soExt}")))
             {
                 throw new NotSupportedException(
                     "Publish succeeded but project assembly not found in the output directory");
diff --git a/modules/mono/editor/GodotTools/GodotTools/Utils/OS.cs b/modules/mono/editor/GodotTools/GodotTools/Utils/OS.cs
index 50c5dc96a7..62140d41bc 100644
--- a/modules/mono/editor/GodotTools/GodotTools/Utils/OS.cs
+++ b/modules/mono/editor/GodotTools/GodotTools/Utils/OS.cs
@@ -44,7 +44,7 @@ namespace GodotTools.Utils
             public const string HTML5 = "javascript";
         }
 
-        private static class DotNetOS
+        public static class DotNetOS
         {
             public const string Win = "win";
             public const string OSX = "osx";