internal/build:compile with c mode,when c file

runtime/internal/clite/os/_os/os.c

@@ -0,0 +1,14 @@
+#include <stdlib.h>
+#include <errno.h>
+
+int cliteClearenv()
+{
+	extern char **environ;
+	if (environ != NULL)
+	{
+		*environ = NULL;
+	}
+	return 0;
+}
+
+int cliteErrno() { return errno; }