Fix build for 10.6 Darwin builders and OpenBSD builers.
LGTM=jsing
R=golang-codereviews, dave, jsing
CC=golang-codereviews
https://golang.org/cl/67710043
The test.bash file generates .so file using gcc, builds the executable
using the go tool and then run it with the $LD_LIBRARY_PATH variable
pointing to the directory where the .so file lives.
Fixes#2982.
R=rsc, remyoudompheng
CC=golang-dev
https://golang.org/cl/5788043