[NativeAOT] Fix transforming [Preserve] into [DynamicDependency] for generic types and generic methods (#18854)

I noticed that we're generating invalid DynamicDependency attributes for generic types and methods. For example for the `void Activated(T sender)` method of `UIKit.UIGestureRecognizer.Callback<T>`:

```c#
// before:
[DynamicDependency("Activated(T)", typeof(UIKit.UIGestureRecognizer.Callback<>))]

// after:
[DynamicDependency("Activated(`0)", "UIKit.UIGestureRecognizer.Callback`1", "Microsoft.MacCatalyst")]
```

---------

Co-authored-by: Simon Rozsival <simon@rozsival.com>

tools/dotnet-linker/AppBundleRewriter.cs

@@ -498,6 +498,19 @@ namespace Xamarin.Linker {
 			}
 		}
 
+		public MethodReference DynamicDependencyAttribute_ctor__String_String_String {
+			get {
+				return GetMethodReference (CorlibAssembly,
+						System_Diagnostics_CodeAnalysis_DynamicDependencyAttribute,
+						".ctor",
+						".ctor(String,String,String)",
+						isStatic: false,
+						System_String,
+						System_String,
+						System_String);
+			}
+		}
+
 		public MethodReference RuntimeTypeHandle_Equals {
 			get {
 				if (configuration.Application.XamarinRuntime == XamarinRuntime.MonoVM) {
@@ -1246,12 +1259,27 @@ namespace Xamarin.Linker {
 
 		public CustomAttribute CreateDynamicDependencyAttribute (string memberSignature, TypeDefinition type)
 		{
+			if (type.HasGenericParameters) {
+				var typeName = Xamarin.Utils.DocumentationComments.GetSignature (type);
+				var assemblyName = type.Module.Assembly.Name.Name;
+				return CreateDynamicDependencyAttribute (memberSignature, typeName, assemblyName);
+			}
+
 			var attribute = new CustomAttribute (DynamicDependencyAttribute_ctor__String_Type);
 			attribute.ConstructorArguments.Add (new CustomAttributeArgument (System_String, memberSignature));
 			attribute.ConstructorArguments.Add (new CustomAttributeArgument (System_Type, type));
 			return attribute;
 		}
 
+		public CustomAttribute CreateDynamicDependencyAttribute (string memberSignature, string typeName, string assemblyName)
+		{
+			var attribute = new CustomAttribute (DynamicDependencyAttribute_ctor__String_String_String);
+			attribute.ConstructorArguments.Add (new CustomAttributeArgument (System_String, memberSignature));
+			attribute.ConstructorArguments.Add (new CustomAttributeArgument (System_String, typeName));
+			attribute.ConstructorArguments.Add (new CustomAttributeArgument (System_String, assemblyName));
+			return attribute;
+		}
+
 		public CustomAttribute CreateDynamicDependencyAttribute (DynamicallyAccessedMemberTypes memberTypes, TypeDefinition type)
 		{
 			var attribute = new CustomAttribute (DynamicDependencyAttribute_ctor__DynamicallyAccessedMemberTypes_Type);

tools/dotnet-linker/DocumentionComments.cs

@@ -28,7 +28,7 @@ namespace Xamarin.Utils {
 		public static string GetSignature (TypeDefinition type)
 		{
 			if (type.IsNested)
-				return type.Name;
+				return type.FullName.Replace ('/', '.');
 			return type.FullName;
 		}
 
@@ -41,6 +41,11 @@ namespace Xamarin.Utils {
 		{
 			var sb = new StringBuilder ();
 			sb.Append (method.Name.Replace ('.', '#'));
+
+			if (method.HasGenericParameters) {
+				sb.Append ($"``{method.GenericParameters.Count}");
+			}
+
 			sb.Append ('(');
 			for (var i = 0; i < method.Parameters.Count; i++) {
 				if (i > 0)
@@ -74,6 +79,17 @@ namespace Xamarin.Utils {
 				return;
 			}
 
+			if (type is GenericParameter gp) {
+				if (gp.Type == GenericParameterType.Type) {
+					sb.Append ('`');
+				} else {
+					sb.Append ("``");
+				}
+
+				sb.Append (gp.Position.ToString ());
+				return;
+			}
+
 			sb.Append (type.FullName.Replace ('/', '.'));
 		}
 	}