the definitive tun offloads branch (#1704)

overlay/checksum/export_arm64_test.go

@@ -0,0 +1,8 @@
+package checksum
+
+// archImpls exposes every hand-written implementation on this architecture
+// for direct testing; see export_amd64_test.go for the rationale. NEON is
+// mandatory in armv8, so it is always available.
+var archImpls = []archImpl{
+	{name: "neon", fn: checksumNEON, available: true},
+}