Write tests for bugs caught while syncing the chain

_Originally posted by @lightclient in https://github.com/ethereum/execution-specs/pull/373#pullrequestreview-779880591_

**Should re-check to see if these have been added to EEST since this issue was written**

This is a bit of a meta-issue for tracking bugs that weren't caught by the tests that were triggered while syncing the chain.

These tests should theoretically get upstreamed to https://github.com/ethereum/tests and checked off here once they're merged.

- [ ] `sstore` persists between transactions (#368)
- [ ] charge gas for `ECRECOVER`
- [ ] `blockhash` should hash only the header, not the block (#373)
- [ ] `signextend` (#375)
- [ ] Push-data extends past end of contract code (#375)
- [ ] Deploying an empty contract (#375)
- [ ] `ECRECOVER` with truncated call data (#445)
- [ ] Logs emitted during `CREATE2` [#466](https://github.com/ethereum/execution-specs/pull/466#discussion_r845540487)
- [ ] Blockhash at 255/256/257