- Parse expressions as opposed to statements for gofmt rewrite patterns. Allows stand-alone types (e.g. []int as patterns) and doesn't require a semicolon at the end (which are now mandatory terminators).
- Parse expressions as opposed to statements for gofmt rewrite patterns.
Allows stand-alone types (e.g. []int as patterns) and doesn't require
a semicolon at the end (which are now mandatory terminators).

- Fix a matcher bug.

R=rsc
CC=golang-dev
http://codereview.appspot.com/179088

tianon/debian-golang,nightlyone/golang,tianon/debian-golang,ssrl/go,h8liu/golang,ssrl/go,gnanderson/go,dsriram/golang,ssrl/go,gnanderson/go,apparentlymart/golang,gnanderson/go,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,dsriram/golang,h8liu/golang,bdwalton/debian-golang,dsriram/golang,dsriram/golang,nightlyone/golang,tv42/old-go,apparentlymart/golang,ssrl/go,dsriram/golang,nightlyone/golang,apparentlymart/golang,nightlyone/golang,gnanderson/go,bdwalton/debian-golang,bdwalton/debian-golang,apparentlymart/golang,h8liu/golang,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,bdwalton/debian-golang,h8liu/golang,ssrl/go,tv42/old-go,dsriram/golang,tv42/old-go,tv42/old-go,h8liu/golang,ssrl/go,tianon/debian-golang,tianon/debian-golang,ssrl/go,pombredanne/go-deleteme,bdwalton/debian-golang,tianon/debian-golang,pombredanne/go-deleteme,bdwalton/debian-golang,nightlyone/golang,tianon/debian-golang,pombredanne/go-deleteme,tianon/debian-golang,h8liu/golang,tv42/old-go,tv42/old-go,tianon/debian-golang,bdwalton/debian-golang,h8liu/golang,bdwalton/debian-golang,pombredanne/go-deleteme,nightlyone/golang,gnanderson/go,apparentlymart/golang,pombredanne/go-deleteme,nightlyone/golang,apparentlymart/golang,tv42/old-go