[x/Programs] Dynamic Arguments

[samliok]

Dynamic Arguments

This PR add support for non fixed length program function args. #576 .

Changes:

• Arguments passed into #[public] functions must be prefixed with a uint32 length.
  • This does not include supported primitives and the Program type
  • after the length prefix, parameters for #[public] functions are serialized using borsh.
• The public proc_macro was updated to call from_raw_pointer on ptrs.
  • This function unpacks the 4 byte length prefix, and converts the subsequent bytes into the specified argument.

example usage

#[public]
pub fn print_name(_: Program, name: String) {
    println!("name: {}", name);
}

/// Mints tokens to multiple recipients.
#[public]
pub fn mint_to_many(program: Program, recipients: Vec<Address>, amounts: Vec<i32>) -> bool {
    assert_eq!(recipients.len(), amounts.len(), "invalid input");

    for (recipient, amount) in recipients.iter().zip(amounts.iter()) {
        mint_to(program, *recipient, *amount as i64);
    }

    true
}

[richardpringle]

Minor change requests

[richardpringle]

Re-approving!

[hexfusion]

Overall I think this a great step forward I have a few cosmetic things to review and in general would like to see the go tests moving to simulator but that can be a followup.

[richardpringle]

🚀