lang: Impl ToAccountMetas for AccountMeta and make state mod pub (#406)

lang/src/account_meta.rs

@@ -0,0 +1,8 @@
+use crate::ToAccountMetas;
+use solana_program::instruction::AccountMeta;
+
+impl ToAccountMetas for AccountMeta {
+    fn to_account_metas(&self, _is_signer: Option<bool>) -> Vec<AccountMeta> {
+        vec![self.clone()]
+    }
+}

lang/src/lib.rs

@@ -32,6 +32,7 @@ use solana_program::pubkey::Pubkey;
 use std::io::Write;
 
 mod account_info;
+mod account_meta;
 mod boxed;
 mod common;
 mod context;
@@ -43,7 +44,7 @@ mod error;
 pub mod idl;
 mod loader;
 mod program_account;
-mod state;
+pub mod state;
 mod sysvar;
 mod vec;