Backport fast alternate io.BytesIO implementation.
Merged r62778, r62779, r62802, r62806, r62807, r62808, r62809, r62844,
r62846, r62952, r62956.
diff --git a/PCbuild/pythoncore.vcproj b/PCbuild/pythoncore.vcproj
index 583a32b..357f71a 100644
--- a/PCbuild/pythoncore.vcproj
+++ b/PCbuild/pythoncore.vcproj
@@ -995,6 +995,10 @@
 				>
 			</File>
 			<File
+				RelativePath="..\Modules\_bytesio.c"
+				>
+			</File>
+			<File
 				RelativePath="..\Modules\_functoolsmodule.c"
 				>
 			</File>