Reason for breakage fixed with CL 11888043.

««« original CL description
undo CL 11683043 / bb75d03e6ccb

Broke arm build.
R=dave

««« original CL description
cc: generate argument pointer maps for C functions.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11683043
»»»

R=golang-dev
CC=golang-dev
https://golang.org/cl/11788043
»»»

TBR=dave
CC=golang-dev
https://golang.org/cl/11789043