code gen error for 	lv += f() fixes asn1 and maybe more
code gen error for
	lv += f()
fixes asn1 and maybe more

R=rsc
CC=golang-dev
http://codereview.appspot.com/2341042

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