Compile error when using the offset_of macro in solana-program crate

[sigurd4]

Problem

On the latest nightly build of rust, the solana-program crate fails to compile because the use of the offset_of macro is considered an experimental feature.

Proposed Solution

Add the feature flag#![feature(offset_of)] to top of the solana-program lib.rs file.

[github-actions]

This repository is no longer in use. Please re-open this issue in the agave repo: https://github.com/anza-xyz/agave