build: check runtime link file

c/c_linux.go

@@ -0,0 +1,15 @@
+//go:build linux
+// +build linux
+
+package c
+
+import _ "unsafe"
+
+//go:linkname Stdin stdin
+var Stdin FilePtr
+
+//go:linkname Stdout stdout
+var Stdout FilePtr
+
+//go:linkname Stderr stderr
+var Stderr FilePtr