Decrement line ends if they end with a carriage return.

[jessetrinity]

Attempting to enter a newline after the #name banner in the collapsed region depicted below causes a crash in Visual Studio.

//#region name

const a = 1;

//#endregion

//#name

Previously the carriage return character \r was being included in the outlining span, as line ends here are determined only by the presence of the new line character \n.

This change simply decrements the line end by one if the line ends with a carriage return \r.

Fixes JS region collapse area after carriage return.

[sheetalkamat]

We need test for this

[jessetrinity]

I suppose I could write a test to make sure we don't consume the \r.

[jessetrinity]

A few things were discussed offline:

1. We definitely want a Visual Studio test for this since it is crashing VS, not just the language service. A fourslash test would be nice, but

2. Fourslash tests don't use CRLF endings (this change is invisible to the existing region tests).

3. In general, TypeScript looks to split lines by new line characters, and deals with carriage returns later. Another example of this behavior here.

[amcasey]

Most of my suggestions apply to parts of the code that you didn't touch, but I think this is a good opportunity to clean it up (and add test coverage).

[jessetrinity]

@sheetalkamat I added a couple of tests. Do we have any concerns about how this could affect VSCode?

[sandersn]

Looks good to me, but get @sheetalkamat's signoff for interactions with VS Code -- or manually test on VS Code.