testing/iotest: add missing tests
Adds missing tests for all the types:
* OneByteReader
* HalfReader
* DataErrReader
* TimeoutReader
* TruncateWriter
* writeLogger
* readLogger
Fixes #33650
Change-Id: I1c773f9f1625ff33a1d0b5a045c72a73a9eca9ce
GitHub-Last-Rev:
2ab650677bb9cad43ea2ce620c9898123c7ec396
GitHub-Pull-Request: golang/go#33651
Reviewed-on: https://go-review.googlesource.com/c/go/+/190259
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>