Update SA1515 to not let one range of trivia affect another

[bjornhellander]

Fixes #3481

The problem as I see it was that the previous code kept state to be able to trigger on the following code:

a(); // Some comment
// Diagnostic wanted here

without triggering on this:

// Some comment
// Diagnostic not wanted here

But this state also leaked over to unrelated chunks of trivia. I replaced the state with more digging in the current trivia, to avoid the reported false positive.

[codecov]

Codecov Report

Merging #3529 (bd21b58) into master (b46e01b) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3529      +/-   ##
==========================================
- Coverage   93.25%   93.25%   -0.01%     
==========================================
  Files        1070     1070              
  Lines      113394   113404      +10     
  Branches     4003     4003              
==========================================
+ Hits       105749   105757       +8     
- Misses       6618     6619       +1     
- Partials     1027     1028       +1     

[sharwell]

Suggested change

	var currentTrivia = triviaList[triviaIndex];
	if (currentTrivia.IsKind(SyntaxKind.EndOfLineTrivia))
	if (triviaList[triviaIndex].IsKind(SyntaxKind.EndOfLineTrivia))

[bjornhellander]

Updated