In order to make the artifacts of go build command preserved under WORK
directory, this change modifies TMPDIR (TEMP/TMP for windows)
environment variables to point to gomobile's tmpdir if -work flag is set.
> gomobile init -work
WORK=/gopath/pkg/gomobile/work-276689736
> ls /gopath/pkg/gomobile/work-276689736
README go-build823903592 openal
android-ndk-r10e go-build858075903
go-build365743399 go-build921886344
> gomobile build -work golang.org/x/mobile/example/basic
WORK=/tmp/gomobile-work-863381843
> ls /tmp/gomobile-work-863381843
go-build102034516 libbasic.so
> gomobile bind -work github.com/hyangah/ivy
WORK=/tmp/gomobile-work-355100962
> ls /tmp/gomobile-work-355100962
android go-build284034365 javac-output
androidlib go_ivy
Change-Id: I2f467e0063bc1c8b8c636a8cd6d100e86a99a91a
Reviewed-on: https://go-review.googlesource.com/12720
Reviewed-by: David Crawshaw <crawshaw@golang.org>
af3e09ede0