tools/build/third_party: Silence cityhash warnings
tools/build/third_party: Silence cityhash warnings

Qining/gapid,google/agi,Qining/gapid,google/gapid,pmuetschard/gapid,pmuetschard/gapid,Qining/gapid,google/gapid,pmuetschard/gapid,Qining/gapid,google/gapid,google/agi,google/agi,google/gapid,pmuetschard/gapid,Qining/gapid,pmuetschard/gapid,google/gapid,Qining/gapid,google/agi,google/gapid,Qining/gapid,pmuetschard/gapid,google/agi,pmuetschard/gapid,google/agi,Qining/gapid,google/gapid,google/gapid,google/agi,pmuetschard/gapid,google/agi