Chunked response with bad Content-Length header to HTTP/1.0 client is broken

A client sends an HTTP/1.0 request through ATS, which gets proxied with HTTP/1.1 to the origin. The origin (which is at fault here, but nonetheless) returns with both

Content-Length: 10
Transfer-Encoding: chunked

and a chunked body which is > 10 bytes long. In this case, ATS should still respond with an HTTP/1.0 response, undoing the chunking, and return with an appropriate CL: header. We do everything, except set the correct Content-Length header, we simply return the erroneous CL header that the Origin provided. This is not allowed in the RFC.

(Originally discovered using Coadvisor).