delete starlark/empty.s (#622)

diff --git a/starlark/empty.s b/starlark/empty.s
deleted file mode 100644
index 3b82169..0000000
--- a/starlark/empty.s
+++ /dev/null
@@ -1,3 +0,0 @@
-// The presence of this file allows the package to use the
-// "go:linkname" hack to call non-exported functions in the
-// Go runtime, such as hardware-accelerated string hashing.