In TypeScript, I augmented the scanner/parser to detect the git-style merge conflict of:

<<<<<  HEAD
code
==== 
code
>>>>  Blah

I then treated this similarly to how C#/VB handle #if #else #endif. Namely, the first part is properly scanned/parsed, and the second part is treated as Inactive-Code.

I also tweaked the classifier so that we do lexical classification in the lower branch of the merge conflict.

This provided a great editing experience around Git conflicts. First off, if you do this, the parser doesn't go off the rails like it does today. Everything remains nicely parseable. Second, editing in the top section works just as normal. You get intellisense, goto-def, etc. Editing in the bottom section is just like editing inside a comment. Nothing gets in your way (like today, where the parser confusion makes everything bad). And things still look pretty good as lexical classification does a decent enough job in that section.

I think we should bring this over to C#/VB to make the experience here much better.