Stubs for some libc headers

programs/bpf/c/sdk/inc/stdio.h

@@ -0,0 +1,2 @@
+#pragma once
+typedef void *FILE;

programs/bpf/c/sdk/inc/stdlib.h

@@ -0,0 +1,2 @@
+#pragma once
+#include <solana_sdk.h>

programs/bpf/c/sdk/inc/string.h

@@ -0,0 +1,7 @@
+#pragma once
+#include <solana_sdk.h>
+
+#define memcpy sol_memcpy
+#define memset sol_memset
+#define strlen sol_strlen
+

programs/bpf/c/sdk/inc/sys/param.h

@@ -0,0 +1 @@
+#pragma once