Merge remote-tracking branch 'aosp/upstream' into master

* aosp/upstream:
  Add . and / to MockFs
  Fix tests with TestMain
  Add a script to regenerate build.ninja.in files
  Test against go 1.7.6 and 1.8.3
  Support TestMain in tests

Test: m -j checkbuild
Change-Id: Ie922dfc59787514b55fd15e7b97728732714e939