Fix error reporting in fsi after a lexer error #14334
Merged
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Fixes #13139, #9631
The problem was that we had some cached lexer state when reading new input during FSI session. If lexer threw an error on a very first token of new input, the cached lexer state would not get updated, so we would assosciate old lexer state with this new token that caused an error.
Now we will invalidate that cached state at the begining of reading new input.