go.tools/oracle: change -pos flag syntax from "file pos-pos" to file:pos-pos.
go.tools/oracle: change -pos flag syntax from "file pos-pos" to file:pos-pos.

Pro: no shell quotation needed.
Con: can't be parsed by (the perpetually useless) Scanf.

R=crawshaw, dgryski
CC=golang-dev
https://golang.org/cl/13441043

dominikh/go-mode.el,emacsmirror/go-mode