cmake: move global project definition to beginning
cmake: move global project definition to beginning

such that necessary cmake variables to detect Cygwin are defined
when setting the C++ standard and we can distinguish.

empiredan/googletest,antidotcb/googletest,empiredan/googletest,gianricardo/googletest,xnagireddy/googletest,jlanecox/googletest,jlanecox/googletest,google/googletest,gianricardo/googletest,jlanecox/googletest,xnagireddy/googletest,xnagireddy/googletest,jlanecox/googletest,antidotcb/googletest,antidotcb/googletest,empiredan/googletest,gianricardo/googletest,xnagireddy/googletest,google/googletest,google/googletest,antidotcb/googletest,google/googletest