Fix C4EV3 functions declaration
This is a GitHub task, make sure to read the info.
In C/C++ you're required to define functions before calling them. If you want to call a function that's defined further down in the source code you can declared it before.
Currently the lab doesn't impose a specific of definition while generating C4EV3 code, so some program fails to compile. Understand the difference between function definition and declaration, and then help us to fix issue #377.
Send a pull request that fixes the issue.