add ProjectAssemblyLoadContext

allows the loading of assemblies in the context of an existing project

test/LoadContextTest/Program.cs

@@ -0,0 +1,51 @@
+using System;
+using System.IO;
+using System.Reflection;
+using Microsoft.DotNet.ProjectModel;
+using Microsoft.DotNet.ProjectModel.Loader;
+using NuGet.Frameworks;
+
+namespace LoadContextTest
+{
+    public class Program
+    {
+        public static int Main(string[] args)
+        {
+            Console.WriteLine("Press enter to start");
+            Console.ReadLine();
+            // Get the path to the project
+            if(args.Length < 1)
+            {
+                Console.Error.WriteLine("Usage: LoadContextTest <path to project>");
+                return 1;
+            }
+            var project = Path.GetFullPath(args[0]);
+
+            // Load the project load context
+            Console.WriteLine($"Creating load context for {project}");
+            var context = ProjectContext.Create(project, FrameworkConstants.CommonFrameworks.DnxCore50, new[] { RuntimeIdentifier.Current });
+            var loadContext = context.CreateLoadContext();
+
+            // Load the project assembly
+            var asm = loadContext.LoadFromAssemblyName(new AssemblyName(context.ProjectFile.Name));
+
+            // Find the helper type and method
+            var type = asm.GetType("TestLibrary.Helper");
+            if(type == null)
+            {
+                Console.Error.WriteLine("Failed to find type");
+                return 1;
+            }
+            var method = type.GetMethod("SayHi", BindingFlags.Public | BindingFlags.Static);
+            if(method == null)
+            {
+                Console.Error.WriteLine("Failed to find method");
+                return 1;
+            }
+
+            // Call it!
+            method.Invoke(null, new object[0]);
+            return 0;
+        }
+    }
+}