The error message was:

warning: macro expansion producing 'defined' has undefined
behavior [-Wexpansion-to-defined]

http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20160118/147239.html

Previously we wrongly handles stream per connection when h2 backend
failed or closed.  If upstream is h2 or spdy, streams which are not
associated to the failed h2 backend are also handled, which is
unnecessary.