adjustable hash code in typecheck of composit literals to get rid of n^2 behavior.
adjustable hash code in
typecheck of composit literals
to get rid of n^2 behavior.

R=rsc
CC=golang-dev
http://codereview.appspot.com/3208041

dsriram/golang,h8liu/golang,h8liu/golang,dsriram/golang,gnanderson/go,gnanderson/go,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,ssrl/go,apparentlymart/golang,ssrl/go,pombredanne/go-deleteme,pombredanne/go-deleteme,gnanderson/go,apparentlymart/golang,gnanderson/go,dsriram/golang,gnanderson/go,tv42/old-go,h8liu/golang,h8liu/golang,apparentlymart/golang,apparentlymart/golang,dsriram/golang,ssrl/go,ssrl/go,pombredanne/go-deleteme,apparentlymart/golang,tv42/old-go,ssrl/go,apparentlymart/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,ssrl/go,apparentlymart/golang,dsriram/golang,h8liu/golang,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,h8liu/golang,gnanderson/go,tv42/old-go,gnanderson/go,h8liu/golang,tv42/old-go,ssrl/go,tv42/old-go