use bpf-entrypoint feature

[buffalojoec]

The rest of the programs we've written in BPF have swapped no-entrypoint for bpf-entrypoint, where the feature is now additive to enable the program ELF's entrypoint binding.

This change brings the Stake program into that same pattern.

[febo]

Looks good. One little comment: we will need to build the program with the bpf-entrypoint feature enabled so the clients tests work:

• https://github.com/solana-program/stake/blob/main/.github/workflows/main.yml#L79

At the moment it is not an issue since we don't have clients tests, so we could do it either in this PR or in a future one.

[2501babe]

ty for doing this, i was aware of the feature switch but it slipped my mind

maybe unrelated to this pr but is there a better ux for the new paradigm than always supplying --features bpf-entrypoint manually? i cloned this to make sure tests run, and i have to provide the flag even to cargo test-sbf. seems a bit annoying that it doesnt do the right thing automatically

[buffalojoec]

maybe unrelated to this pr but is there a better ux for the new paradigm than always supplying --features bpf-entrypoint manually? i cloned this to make sure tests run, and i have to provide the flag even to cargo test-sbf. seems a bit annoying that it doesnt do the right thing automatically

I was considering adding it to the build-sbf and test-sbf commands, but I wasn't totally sure if we wanted to make it a global standard for the platform tools. It could just be optionally enabled for crates that specify the feature. Wdyt?

[2501babe]

yea if added it would need to check if the feature exists in Cargo.tom because if you specify the flag and the feature doesnt exist then cargo will halt with an error