[libunwind] Fflush stderr after each log message
In most configs, stderr is line buffered by default, but in some
cases on Windows (running in git bash, or running in Wine) stderr
can end up fully buffered.
See 2ec75a0869ab01fa9caf310e8a31eb7716182d30 for a similar change
for the output from lit itself.
This has no effect on libunwind when the log messages aren't enabled
via the environment variables.
Differential Revision: https://reviews.llvm.org/D147632
GitOrigin-RevId: a33d5a9939aa3c0bcdb0f951c0bc4b96071bda2c
1 file changed
