=htc #16388 fix StackOverflowException during chunk parsing

Because of the test changes it may collide with other PRs.

Fixes #16388.

/cc @sirthias 
Hmm. Considering that emit is just "result += output" can't you piggyback on the trampolining features of the interpreter instead -- i.e. make the parser completely pull based instead of collecting into the result ListBuffer? Maybe it is not possible, but it is something to consider.