cmd/go: quote command line arguments in debug output

Debug output from go test -x may contain empty arguments.
This CL quotes arguments if needed. E.g. the output of
go test -x is now
  .../6g -o ./_go_.6 -p testmain -complete -D "" -I . -I $WORK ./_testmain.go
which is easier to grasp.

R=golang-dev, bradfitz, minux.ma, r
CC=golang-dev
https://codereview.appspot.com/8633043

Committer: Rob Pike <r@golang.org>
cmd/go: quote command line arguments in debug output

Debug output from go test -x may contain empty arguments.
This CL quotes arguments if needed. E.g. the output of
go test -x is now
  .../6g -o ./_go_.6 -p testmain -complete -D "" -I . -I $WORK ./_testmain.go
which is easier to grasp.

R=golang-dev, bradfitz, minux.ma, r
CC=golang-dev
https://codereview.appspot.com/8633043

Committer: Rob Pike <r@golang.org>