new detector: Unnamed Return Shadows Local

[xternet]

Detects when return function without return statement has unnamed variables inside returns.

Example:

pragma solidity ^0.8.0;

contract Bug {
    function unnamed() external view returns(uint) {
        uint val = 1;
    } //returns 0
}

[lgtm-com]

This pull request introduces 1 alert when merging 9fd5aaf into 996712c - view on LGTM.com

new alerts:

• 1 for Unused import