Fixed compile error on windows.
diff --git a/PCbuild/pythoncore.vcproj b/PCbuild/pythoncore.vcproj
index 0d3d71e..1b9056a 100644
--- a/PCbuild/pythoncore.vcproj
+++ b/PCbuild/pythoncore.vcproj
@@ -1459,6 +1459,10 @@
 				>
 			</File>
 			<File
+				RelativePath="..\Objects\memoryobject.c"
+				>
+			</File>
+			<File
 				RelativePath="..\Objects\methodobject.c"
 				>
 			</File>