testing: add Output
Output is a method on T, B and F. It provides an io.Writer that writes
to the same test output stream as TB.Log. The new output writer is
used to refactor the implementation of Log. It maintains the formatting
provided by Log while making call site information optional.
Additionally, it provides buffering of log messages.
Co-authored-by: Aleks Fazlieva <britishrum@users.noreply.github.com>
Fixes #59928.
Change-Id: I29090b3d4f61f7334388b373ec18750d5637aafa
GitHub-Last-Rev:
18af0e15262494f2074d545a6042b079d62301a2
GitHub-Pull-Request: golang/go#71575
Reviewed-on: https://go-review.googlesource.com/c/go/+/646956
Reviewed-by: Arati <artichaut2023@gmail.com>
Auto-Submit: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>