[jnimarshalmethod-gen] Support resolving types from active assembly

For reasons I'm not going to investigate, if an interface type is
defined in the assembly that `jnimarshalmethod-gen` is processing,
`Assembly.Location` will be the empty string, which causes an error:

	% dotnet bin/Release-net8.0/jnimarshalmethod-gen.dll bin/TestRelease-net8.0/Java.Base-Tests.dll -v -v --keeptemp
	…
	error JM4006: jnimarshalmethod-gen: Unable to process assembly 'bin/TestRelease-net8.0/Java.Base-Tests.dll'
	Name can not be empty
	System.ArgumentException: Name can not be empty
	   at Mono.Cecil.AssemblyNameReference.Parse(String fullName)
	   at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName, ReaderParameters parameters) in /Users/runner/work/1/s/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs:line 261
	   at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName) in /Users/runner/work/1/s/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs:line 256
	   at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.GetAssembly(String fileName) in /Users/runner/work/1/s/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs:line 251
	   at Xamarin.Android.Tools.JniMarshalMethodGenerator.Extensions.NeedsMarshalMethod(MethodDefinition md, DirectoryAssemblyResolver resolver, TypeDefinitionCache cache, MethodInfo method, String& name, String& methodName, String& signature) in /Users/runner/work/1/s/tools/jnimarshalmethod-gen/App.cs:line 790
	   at Xamarin.Android.Tools.JniMarshalMethodGenerator.App.CreateMarshalMethodAssembly(String path) in /Users/runner/work/1/s/tools/jnimarshalmethod-gen/App.cs:line 538
	   at Xamarin.Android.Tools.JniMarshalMethodGenerator.App.ProcessAssemblies(List`1 assemblies) in /Users/runner/work/1/s/tools/jnimarshalmethod-gen/App.cs:line 285

Update `App.NeedsMarshalMethod()` so that when the assembly Location
is not present, `DirectoryAssemblyResolver.Resolve(assemblyName)`
is instead used.  This prevents the `ArgumentException`.

Author: jonpryor

build-tools/Java.Interop.Sdk/Sdk/Sdk.targets

@@ -160,7 +160,7 @@
     </XmlPeek>
     <PropertyGroup>
       <DefineConstants>$(DefineConstants);$([System.String]::Copy('$(_GeneratedDefineConstants)').Replace ('%24(DefineConstants);', ''))</DefineConstants>
-    </PropertyGroup>    
+    </PropertyGroup>
   </Target>
 
   <Target Name="_CleanupManagedBinding" />

tools/jnimarshalmethod-gen/App.cs

@@ -786,8 +786,12 @@ public static bool NeedsMarshalMethod (this MethodDefinition md, DirectoryAssemb
 				if (iface.IsGenericType)
 					continue;
 
+				var location = iface.Assembly.Location;
+				var ad = string.IsNullOrEmpty (location)
+					? resolver.Resolve (iface.Assembly.GetName ().Name)
+					: resolver.GetAssembly (location);
+
 				var ifaceMap = method.DeclaringType.GetInterfaceMap (iface);
-				var ad = resolver.GetAssembly (iface.Assembly.Location);
 				var id = ad.MainModule.GetType (iface.GetCecilName ());
 
 				if (id == null) {