go/types, types2: make error handling more similar
This change will make error handling between go/types and types2
more similar which will in turn allow more go/types files to be
generated from types2 sources.
Specifically:
- add Checker.newError to create error_ objects
- s/error_.errorf/error_.addf/
- remove error_.String (use error_.msg instead)
- replace Checker.report with error_.report
- make error_.report as similar as currently possible
- adjust dependencies
The new code consistently uses newError/addf/report
to report all errors.
Change-Id: Ibd6fd743a4f7746b4aa6b93fe768814dad9ee9c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/566096 Reviewed-by: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>