Since the Go runtime treats it specially, so must the pointer analysis.
Details:
- Combine object.{val,typ} fields into 'data interface{}'.
It may now hold a string, describing an instrinsically
allocated object such as the command-line args.
- extend Label accordingly; add Label.ReflectType() accessor.
Also: document pointer analysis algorithm classification.
R=crawshaw
CC=golang-dev
https://golang.org/cl/14156043