Windows, bazel client: compile more with MSVC
Windows, bazel client: compile more with MSVC

In this commit:
- update GetOutputRoot with a MSVC-specific code
  path, plus add more env vars to check for the
  temp directory path in the MSYS-specific code
  path
- add error handling to GetSelfPath

--
MOS_MIGRATED_REVID=138611621

dslomov/bazel-windows,damienmg/bazel,ButterflyNetwork/bazel,akira-baruah/bazel,LuminateWireless/bazel,cushon/bazel,ulfjack/bazel,snnn/bazel,damienmg/bazel,juhalindfors/bazel-patches,Asana/bazel,safarmer/bazel,zhexuany/bazel,meteorcloudy/bazel,akira-baruah/bazel,cushon/bazel,Asana/bazel,spxtr/bazel,safarmer/bazel,perezd/bazel,kchodorow/bazel,kchodorow/bazel-1,damienmg/bazel,bazelbuild/bazel,aehlig/bazel,mikelikespie/bazel,kchodorow/bazel-1,snnn/bazel,mbrukman/bazel,aehlig/bazel,zhexuany/bazel,aehlig/bazel,damienmg/bazel,juhalindfors/bazel-patches,mbrukman/bazel,perezd/bazel,snnn/bazel,bazelbuild/bazel,twitter-forks/bazel,safarmer/bazel,cushon/bazel,spxtr/bazel,damienmg/bazel,davidzchen/bazel,dslomov/bazel,twitter-forks/bazel,katre/bazel,kchodorow/bazel-1,werkt/bazel,meteorcloudy/bazel,dropbox/bazel,dslomov/bazel,dropbox/bazel,kchodorow/bazel-1,spxtr/bazel,mikelikespie/bazel,spxtr/bazel,mbrukman/bazel,bazelbuild/bazel,werkt/bazel,ButterflyNetwork/bazel,katre/bazel,twitter-forks/bazel,Asana/bazel,zhexuany/bazel,spxtr/bazel,damienmg/bazel,kchodorow/bazel,kchodorow/bazel,damienmg/bazel,dslomov/bazel-windows,meteorcloudy/bazel,ulfjack/bazel,LuminateWireless/bazel,dslomov/bazel,davidzchen/bazel,Asana/bazel,kchodorow/bazel-1,variac/bazel,dslomov/bazel-windows,twitter-forks/bazel,twitter-forks/bazel,cushon/bazel,davidzchen/bazel,dslomov/bazel,akira-baruah/bazel,variac/bazel,katre/bazel,davidzchen/bazel,variac/bazel,aehlig/bazel,dslomov/bazel-windows,zhexuany/bazel,ulfjack/bazel,perezd/bazel,kchodorow/bazel-1,katre/bazel,dslomov/bazel-windows,perezd/bazel,dropbox/bazel,dropbox/bazel,bazelbuild/bazel,ulfjack/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,spxtr/bazel,davidzchen/bazel,LuminateWireless/bazel,kchodorow/bazel,dslomov/bazel,spxtr/bazel,LuminateWireless/bazel,aehlig/bazel,mbrukman/bazel,cushon/bazel,hermione521/bazel,kchodorow/bazel,werkt/bazel,safarmer/bazel,perezd/bazel,twitter-forks/bazel,LuminateWireless/bazel,werkt/bazel,katre/bazel,LuminateWireless/bazel,dslomov/bazel-windows,werkt/bazel,juhalindfors/bazel-patches,mbrukman/bazel,zhexuany/bazel,hermione521/bazel,snnn/bazel,meteorcloudy/bazel,ulfjack/bazel,safarmer/bazel,aehlig/bazel,variac/bazel,mikelikespie/bazel,bazelbuild/bazel,juhalindfors/bazel-patches,dslomov/bazel,juhalindfors/bazel-patches,Asana/bazel,variac/bazel,snnn/bazel,Asana/bazel,meteorcloudy/bazel,akira-baruah/bazel,variac/bazel,davidzchen/bazel,kchodorow/bazel,hermione521/bazel,aehlig/bazel,akira-baruah/bazel,werkt/bazel,mikelikespie/bazel,katre/bazel,mbrukman/bazel,variac/bazel,ulfjack/bazel,juhalindfors/bazel-patches,zhexuany/bazel,hermione521/bazel,mikelikespie/bazel,mikelikespie/bazel,dropbox/bazel,dslomov/bazel,meteorcloudy/bazel,davidzchen/bazel,cushon/bazel,perezd/bazel,dropbox/bazel,akira-baruah/bazel,hermione521/bazel,ButterflyNetwork/bazel,kchodorow/bazel,snnn/bazel,safarmer/bazel,snnn/bazel,ulfjack/bazel,Asana/bazel,perezd/bazel,ButterflyNetwork/bazel,hermione521/bazel,juhalindfors/bazel-patches