[5.9] Fix newline parsing at trailing trivia

[TTOzzi]

• Explanation: Previously, we would not consider newlines inside comments as making a token start on a new line. Because of this we would reject the following, saying that the two elements should be separated by a semicolon

let a = 1 /*
*/let b = 2

• Scope: Parsing of tokens that start with a multi-line comment
• Risk: Relatively low
• Testing: Added a test case
• Reviewer: rdar://108762344 / Statements that are separated by a newline inside a block comment are not accepted #1626

[TTOzzi]

I ran format.py before opening the PR, and it made this change 🤔
Should I include this in this PR?

[ahoppen]

Ah, that’s because the 5.9 swift-format doesn’t add a space here. It shouldn’t be included in the PR or CI will complain that the release/5.9 branch is not formatted correctly according to the release/5.9 branch of swift-format.

[TTOzzi]

Aha, I understand. I removed the formatting commit. Thank you for explaining it 🙂

[TTOzzi]

This is also the same.

[ahoppen]

@swift-ci Please test