[Bug libstdc++/88999] [9/10 Regression] testcases using in_avail() fail on nios2-elf

[sandra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88999

--- Comment #5 from sandra at gcc dot gnu.org ---
This may be the same as PR 79193.  I'll check and see whether the patch
attached to that issue fixes it.