cmd/benchsave: add header flag for specifying common keys

This allows easily adding additional information when uploading
existing files. Example usage:

benchsave -header <(echo goarch: arm; echo goos: linux) *.log

Change-Id: I46afafd39d8314d9c06c209f868b71cd5e58c63a
Reviewed-on: https://go-review.googlesource.com/35350
Reviewed-by: Russ Cox <rsc@golang.org>
2 files changed
tree: bd19913d9c31beee3ffe7c0725661ef246d52b15
  1. cmd/
  2. storage/
  3. AUTHORS
  4. CONTRIBUTING.md
  5. CONTRIBUTORS
  6. LICENSE
  7. PATENTS
  8. README