lang: Change entrypoint visibility (#510)

lang/syn/src/codegen/program/entry.rs

@@ -50,7 +50,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
         /// The `entry` function here, defines the standard entry to a Solana
         /// program, where execution begins.
         #[cfg(not(feature = "no-entrypoint"))]
-        fn entry(program_id: &Pubkey, accounts: &[AccountInfo], data: &[u8]) -> ProgramResult {
+        pub fn entry(program_id: &Pubkey, accounts: &[AccountInfo], data: &[u8]) -> ProgramResult {
             #[cfg(feature = "anchor-debug")]
             {
                 msg!("anchor-debug is active");