Temporarily add System.Runtime facade reference explicitly, since the host...

Temporarily add System.Runtime facade reference explicitly, since the host object moved to portable lib

src/Interactive/HostTest/InteractiveHostTests.cs

@@ -841,11 +841,15 @@ public void ReferencePaths()
             CompileLibrary(directory, assemblyName + ".dll", assemblyName, @"public class C { }");
             var rspFile = Temp.CreateFile();
             rspFile.WriteAllText("/rp:" + directory.Path);
-            var task = Host.ResetAsync(new InteractiveHostOptions(initializationFile: rspFile.Path, culture: CultureInfo.InvariantCulture));
-            task.Wait();
+
+            Host.ResetAsync(new InteractiveHostOptions(initializationFile: rspFile.Path, culture: CultureInfo.InvariantCulture)).Wait();
+
             Execute(
 $@"#r ""{assemblyName}.dll""
 typeof(C).Assembly.GetName()");
+
+            Assert.Equal("", ReadErrorOutputToEnd());
+
             var output = SplitLines(ReadOutputToEnd());
             Assert.Equal(2, output.Length);
             Assert.Equal("Loading context from '" + Path.GetFileName(rspFile.Path) + "'.", output[0]);

src/Scripting/Core/Script.cs

@@ -199,6 +199,12 @@ public Compilation GetCompilation()
                     {
                         var globalsTypeAssembly = MetadataReference.CreateFromAssemblyInternal(GlobalsType.GetTypeInfo().Assembly);
                         references.Add(globalsTypeAssembly);
+
+                        // TODO: remove
+                        var systemRuntimeFacade = MetadataReference.CreateFromAssemblyInternal(
+                            Assembly.Load(new AssemblyName("System.Runtime, Version=4.0.20.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")));
+
+                        references.Add(systemRuntimeFacade);
                     }
 
                     if (languageRuntimeReferenceOpt != null)