Fix treatment of symbolic refs in PushOp
Fix treatment of symbolic refs in PushOp

We need to use the symbolic ref name when mirroring, as we flatten
it out to a normal ref on the remote site.  This prevents cases
where we needed to push both "HEAD" and "refs/heads/master" as the
former was a symbolic-ref to the latter.

Signed-off-by: Shawn O. Pearce <f3ea74d906fa9fe97c1fef6bad9cb871485c7045@google.com>

renchaorevee/gerrit,ckamm/gerrit,netroby/gerrit,Seinlin/gerrit,rtyley/mini-git-server,keerath/gerrit_newssh,supriyantomaftuh/gerrit,midnightradio/gerrit,Seinlin/gerrit,thinkernel/gerrit,Saulis/gerrit,atdt/gerrit,WANdisco/gerrit,basilgor/gerrit,GerritCodeReview/gerrit,thesamet/gerrit,CandyShop/gerrit,Team-OctOS/host_gerrit,anminhsu/gerrit,ashang/aaron-gerrit,cjh1/gerrit,hdost/gerrit,quyixia/gerrit,hdost/gerrit,netroby/gerrit,ckamm/gerrit,dwhipstock/gerrit,MerritCR/merrit,austinchic/Gerrit,bpollack/gerrit,ckamm/gerrit,renchaorevee/gerrit,supriyantomaftuh/gerrit,quyixia/gerrit,gcoders/gerrit,joshuawilson/merrit,hdost/gerrit,atdt/gerrit,MerritCR/merrit,jackminicloud/test,basilgor/gerrit,Overruler/gerrit,dwhipstock/gerrit,1yvT0s/gerrit,ashang/aaron-gerrit,catrope/gerrit,sudosurootdev/gerrit,TonyChai24/test,duboisf/gerrit,1yvT0s/gerrit,MerritCR/merrit,jeblair/gerrit,m1kah/gerrit-contributions,gracefullife/gerrit,WANdisco/gerrit,supriyantomaftuh/gerrit,Overruler/gerrit,skurfuerst/gerrit,teamblueridge/gerrit,renchaorevee/gerrit,gcoders/gerrit,anminhsu/gerrit,Overruler/gerrit,atdt/gerrit,quyixia/gerrit,teamblueridge/gerrit,zommarin/gerrit,bpollack/gerrit,dwhipstock/gerrit,evanchueng/gerrit,basilgor/gerrit,m1kah/gerrit-contributions,GerritCodeReview/gerrit,sudosurootdev/gerrit,qtproject/qtqa-gerrit,MerritCR/merrit,Distrotech/gerrit,gracefullife/gerrit,ashang/aaron-gerrit,teamblueridge/gerrit,Distrotech/gerrit,makholm/gerrit-ceremony,anminhsu/gerrit,CandyShop/gerrit,Distrotech/gerrit,jackminicloud/test,1yvT0s/gerrit,Seinlin/gerrit,supriyantomaftuh/gerrit,WANdisco/gerrit,thinkernel/gerrit,WANdisco/gerrit,Distrotech/gerrit,joshuawilson/merrit,Distrotech/gerrit,makholm/gerrit-ceremony,Saulis/gerrit,basilgor/gerrit,quyixia/gerrit,renchaorevee/gerrit,teamblueridge/gerrit,Distrotech/gerrit,GerritCodeReview/gerrit,supriyantomaftuh/gerrit,bpollack/gerrit,GerritCodeReview/gerrit,1yvT0s/gerrit,bpollack/gerrit,hdost/gerrit,skurfuerst/gerrit,m1kah/gerrit-contributions,jackminicloud/test,hdost/gerrit,duboisf/gerrit,ashang/aaron-gerrit,bootstraponline-archive/gerrit-mirror,netroby/gerrit,GerritCodeReview/gerrit,TonyChai24/test,CandyShop/gerrit,basilgor/gerrit,thesamet/gerrit,austinchic/Gerrit,netroby/gerrit,jackminicloud/test,Seinlin/gerrit,midnightradio/gerrit,duboisf/gerrit,midnightradio/gerrit,makholm/gerrit-ceremony,anminhsu/gerrit,Saulis/gerrit,pkdevbox/gerrit,dwhipstock/gerrit,Distrotech/gerrit,gcoders/gerrit,bootstraponline-archive/gerrit-mirror,netroby/gerrit,gcoders/gerrit,dwhipstock/gerrit,evanchueng/gerrit,duboisf/gerrit,TonyChai24/test,WANdisco/gerrit,gracefullife/gerrit,midnightradio/gerrit,netroby/gerrit,Overruler/gerrit,WANdisco/gerrit,jeblair/gerrit,TonyChai24/test,Team-OctOS/host_gerrit,Seinlin/gerrit,joshuawilson/merrit,joshuawilson/merrit,quyixia/gerrit,catrope/gerrit,bootstraponline-archive/gerrit-mirror,GerritCodeReview/gerrit-attic,evanchueng/gerrit,supriyantomaftuh/gerrit,renchaorevee/gerrit,hdost/gerrit,supriyantomaftuh/gerrit,MerritCR/merrit,midnightradio/gerrit,evanchueng/gerrit,WANdisco/gerrit,keerath/gerrit_newssh,sudosurootdev/gerrit,makholm/gerrit-ceremony,gerrit-review/gerrit,quyixia/gerrit,thesamet/gerrit,Team-OctOS/host_gerrit,ckamm/gerrit,Saulis/gerrit,pkdevbox/gerrit,joshuawilson/merrit,GerritCodeReview/gerrit,hdost/gerrit,jackminicloud/test,catrope/gerrit,pkdevbox/gerrit,thinkernel/gerrit,gcoders/gerrit,gracefullife/gerrit,qtproject/qtqa-gerrit,joshuawilson/merrit,keerath/gerrit_newssh,GerritCodeReview/gerrit,thinkernel/gerrit,midnightradio/gerrit,Seinlin/gerrit,bootstraponline-archive/gerrit-mirror,Seinlin/gerrit,Saulis/gerrit,GerritCodeReview/gerrit,TonyChai24/test,dwhipstock/gerrit,zommarin/gerrit,atdt/gerrit,MerritCR/merrit,gerrit-review/gerrit,thinkernel/gerrit,dwhipstock/gerrit,Overruler/gerrit,zommarin/gerrit,qtproject/qtqa-gerrit,zommarin/gerrit,atdt/gerrit,cjh1/gerrit,jackminicloud/test,1yvT0s/gerrit,CandyShop/gerrit,pkdevbox/gerrit,Team-OctOS/host_gerrit,pkdevbox/gerrit,TonyChai24/test,qtproject/qtqa-gerrit,gerrit-review/gerrit,m1kah/gerrit-contributions,gcoders/gerrit,austinchic/Gerrit,GerritCodeReview/gerrit-attic,joshuawilson/merrit,bpollack/gerrit,ashang/aaron-gerrit,Team-OctOS/host_gerrit,qtproject/qtqa-gerrit,cjh1/gerrit,cjh1/gerrit,renchaorevee/gerrit,thesamet/gerrit,MerritCR/merrit,rtyley/mini-git-server,Team-OctOS/host_gerrit,austinchic/Gerrit,netroby/gerrit,GerritCodeReview/gerrit-attic,TonyChai24/test,Overruler/gerrit,joshuawilson/merrit,sudosurootdev/gerrit,pkdevbox/gerrit,catrope/gerrit,gracefullife/gerrit,thesamet/gerrit,bpollack/gerrit,MerritCR/merrit,anminhsu/gerrit,CandyShop/gerrit,gerrit-review/gerrit,bootstraponline-archive/gerrit-mirror,bootstraponline-archive/gerrit-mirror,teamblueridge/gerrit,thinkernel/gerrit,anminhsu/gerrit,keerath/gerrit_newssh,Team-OctOS/host_gerrit,jeblair/gerrit,renchaorevee/gerrit,gerrit-review/gerrit,jeblair/gerrit,thinkernel/gerrit,anminhsu/gerrit,qtproject/qtqa-gerrit,zommarin/gerrit,keerath/gerrit_newssh,jackminicloud/test,sudosurootdev/gerrit,skurfuerst/gerrit,pkdevbox/gerrit,quyixia/gerrit,Saulis/gerrit,gerrit-review/gerrit,ckamm/gerrit,gerrit-review/gerrit,gcoders/gerrit,evanchueng/gerrit,skurfuerst/gerrit,thesamet/gerrit,thesamet/gerrit,qtproject/qtqa-gerrit