Bazel client, Windows: make server mode work 
Bazel client, Windows: make server mode work 

Fix blaze_util_windows::ConvertAbsolutePaths,
which happens to have been the culprit why the
MSYS-less Bazel would always kill the running
server.

Fixes https://github.com/bazelbuild/bazel/issues/2672
See https://github.com/bazelbuild/bazel/issues/2107

--
Change-Id: I873a78c737a6d6906ac7db9bcd0e7186e17bd7ca
Reviewed-on: https://cr.bazel.build/9355
PiperOrigin-RevId: 150052180
MOS_MIGRATED_REVID=150052180

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