Fixup the MSYS path for the Windows build.
Fixup the MSYS path for the Windows build.

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