Lexer misses the last comment after a const declaration

[kayagokalp]

lex_commented() does not pick up // This is a comment next to a const with the following example:

contract;

const /* TEST: blah blah tests */ TEST: u16 = 10; // This is a comment next to a const

I believe this example is a valid sway program so while lexing we should include the last comment to the token stream.

I do suspect this happens not just after const but after the last semicolon in the source file (if there is no encapsulating braces etc). (Need to test this feeling and if that is the case I will update the title)

Realized while testing #2311

[mohammadfawaz]

I'm assuming the fix for this issue is purely in sway-parse right? I'm going to add the P: critical label and remove the formatter label. Please let me know if you disagree.

[AlicanC]

Fixed in #2516 as a side effect.