The compiledir pattern compiles all files xxx.dir/*.go
in lexicographic order (which is assumed to coincide with
the topological order of dependencies).
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6440048
This change is necessary to make the run shell script work
again, but it is not sufficient as bug424.go's execution line
does not name the package that it imports.
R=golang-dev, gri, rsc
CC=golang-dev
https://golang.org/cl/5771043