allow odd number of characters in hex constants

[hackaugusto]

the following code:

begin
    push.0x100
end

fails to assemble with the following error code:

Failed to parse program file `t.masm` - parsing error at [2:5]: malformed instruction 'push.0x100', parameter 0x100 is invalid: hex string '100' does not contain an even number of characters

However, 0x100 is a valid representation of the number 128. As an example, the following program:

fn main() {
    println!("{}", format!("0x{:02x}", 256));
}

Will print 0x100 when executed. This is causing test failures in miden-base when similar logic is used to format an account id for testing.

[Bisht13]

Is this fixed? If not, I can pick this up.

[bitwalker]

I believe the parser still requires there to be an even number of hex digits, so I believe this is still an open issue @Bisht13