Add ContextToMethodDescriptor extension class (#376)

Cpp2IL.Core/Utils/AsmResolver/ContextToMethodDescriptor.cs

@@ -0,0 +1,52 @@
+using System.Linq;
+using AsmResolver.DotNet;
+using AsmResolver.DotNet.Signatures;
+using Cpp2IL.Core.Model.Contexts;
+
+namespace Cpp2IL.Core.Utils.AsmResolver;
+
+public static class ContextToMethodDescriptor
+{
+    private static MethodDefinition GetMethodDefinition(this MethodAnalysisContext context)
+    {
+        return context.GetExtraData<MethodDefinition>("AsmResolverMethod") ?? throw new($"AsmResolver method not found in method analysis context for {context}");
+    }
+
+    private static MethodSignature ToMethodSignature(this MethodAnalysisContext context, ModuleDefinition parentModule)
+    {
+        var returnType = context.ReturnTypeContext.ToTypeSignature(parentModule);
+        var parameters = context.Parameters.Select(p => p.ToTypeSignature(parentModule));
+
+        var genericParameterCount = context.Definition?.GenericContainer?.genericParameterCount ?? 0;
+
+        return context.IsStatic
+            ? MethodSignature.CreateStatic(returnType, genericParameterCount, parameters)
+            : MethodSignature.CreateInstance(returnType, genericParameterCount, parameters);
+    }
+
+    public static IMethodDescriptor ToMethodDescriptor(this MethodAnalysisContext context, ModuleDefinition parentModule)
+    {
+        if (context is ConcreteGenericMethodAnalysisContext concreteMethod)
+        {
+            var memberReference = new MemberReference(
+                concreteMethod.DeclaringType?.ToTypeSignature(parentModule).ToTypeDefOrRef(),
+                concreteMethod.Name,
+                concreteMethod.BaseMethodContext.ToMethodSignature(parentModule));
+
+            var methodGenericParameters = concreteMethod.ResolveMethodGenericParameters();
+            if (methodGenericParameters.Length == 0)
+            {
+                return parentModule.DefaultImporter.ImportMethod(memberReference);
+            }
+            else
+            {
+                var typeSignatures = methodGenericParameters.Select(p => p.ToTypeSignature(parentModule)).ToArray();
+                return parentModule.DefaultImporter.ImportMethod(memberReference.MakeGenericInstanceMethod(typeSignatures));
+            }
+        }
+        else
+        {
+            return parentModule.DefaultImporter.ImportMethod(context.GetMethodDefinition());
+        }
+    }
+}