spec: use the term "lexical token" (rather then "lexical symbol")
spec: use the term "lexical token" (rather then "lexical symbol")

Fix for minor inconsistency.

R=golang-dev, iant
CC=golang-dev
http://codereview.appspot.com/5709058

dsriram/golang,gnanderson/go,pombredanne/go-deleteme,dsriram/golang,gnanderson/go,dsriram/golang,gnanderson/go,apparentlymart/golang,pombredanne/go-deleteme,apparentlymart/golang,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,pombredanne/go-deleteme,apparentlymart/golang,tv42/old-go,tv42/old-go,dsriram/golang,gnanderson/go,apparentlymart/golang,apparentlymart/golang,gnanderson/go,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,dsriram/golang,gnanderson/go,tv42/old-go,apparentlymart/golang,tv42/old-go,apparentlymart/golang