Includes more enhancements to debugging output.
Updates #44816.
Change-Id: I5b21815cf37ed21e7dec6c06f538090f32260203
Reviewed-on: https://go-review.googlesource.com/c/go/+/299409
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
