cmd/guru: emacs: interpret byte offsets correctly
cmd/guru: emacs: interpret byte offsets correctly

Change-Id: Id506c6c0b3f3c585781bfc38df1b665d507a7c33
Reviewed-on: https://go-review.googlesource.com/22019
Reviewed-by: Alan Donovan <7069e9552f9d110b0a0f326b96f22f63fb99dfc1@google.com>

golang/tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,golang/tools,syreclabs/go-tools,golang/tools,syreclabs/go-tools