Traits with Duplicate Names in Function Signatures are Allowed

[sskeirik]

Describe the bug
On master branch, when a contract contains a trait definition like the following:

(define-trait double-method (
  (foo (uint) (response uint uint))
  (foo (bool) (response bool bool))
))

Then only the last copy of foo is kept as part of the processed trait's definition.
This means that we can then successfully launch a contract like the following:

(impl-trait 'SP8CW062DS1XAZJJXWKSM9EMMDD51BRVFMY8MBX6.double-trait.double-method)
(define-read-only (foo (x bool)) (ok x))

Steps To Reproduce
If the first contract is stored in a file double-trait.clar and the second contract is stored in a file impl-double-trait.clar, then the CLI invocation to test would be:

clarity-cli initialize initial-allocations.json vm-state.db
clarity-cli launch SP8CW062DS1XAZJJXWKSM9EMMDD51BRVFMY8MBX6.double-trait double-trait.clar vm-state.db
clarity-cli launch SP8CW062DS1XAZJJXWKSM9EMMDD51BRVFMY8MBX6.impl-double-trait impl-double-trait.clar vm-state.db

Expected behavior
I expect that the type checker will reject contracts with traits that contain two function signatures with the same name, even if they are identical otherwise.

Environment (please complete the following information):

• OS: WSL 2 Arch Linux
• Rust version: 1.61.0
• Clarity version: https://github.com/stacks-network/stacks-blockchain/tree/08c163bab484954b3934515ee7bf60848f52ed4a

Additional context
N/A

[jcnelson]

Thanks for your report! We're looking into it. A proper fix would be to address this in the 2.1 upgrade, but in all likelihood the tooling could also warn against this.

[jcnelson]

Fixed by #3251