cmd/trace: merge testdata debugging tools into the trace tool
Currently internal/trace/testdata contains three debugging tools which
were written early in the trace rewrite for debugging. Two of these are
completely redundant with go tool trace -d=1 and go tool trace -d=2. The
only remaining one landed in the last cycle and could easily also be
another debug mode.
This change thus merges gotraceeventstats into go tool trace as a new
debug mode, and updates the debug mode flag (-d) to accept a string,
giving each mode a more descriptive name.
Change-Id: I170f30440691b81de846b4e247deb3d0982fc205
Reviewed-on: https://go-review.googlesource.com/c/go/+/593975 Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>