Cross platform code for shell command execution: fix compiler flags
Cross platform code for shell command execution: fix compiler flags

rserban/chrono,hsu/chrono,armanpazouki/chrono,rserban/chrono,projectchrono/chrono,andrewseidl/chrono,Bryan-Peterson/chrono,dariomangoni/chrono,dariomangoni/chrono,jcmadsen/chrono,armanpazouki/chrono,Milad-Rakhsha/chrono,tjolsen/chrono,amelmquist/chrono,amelmquist/chrono,armanpazouki/chrono,projectchrono/chrono,Bryan-Peterson/chrono,armanpazouki/chrono,rserban/chrono,rserban/chrono,tjolsen/chrono,jcmadsen/chrono,hsu/chrono,Milad-Rakhsha/chrono,amelmquist/chrono,hsu/chrono,amelmquist/chrono,andrewseidl/chrono,jcmadsen/chrono,andrewseidl/chrono,andrewseidl/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,armanpazouki/chrono,armanpazouki/chrono,tjolsen/chrono,amelmquist/chrono,PedroTrujilloV/chrono,tjolsen/chrono,andrewseidl/chrono,dariomangoni/chrono,PedroTrujilloV/chrono,projectchrono/chrono,Bryan-Peterson/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,rserban/chrono,rserban/chrono,projectchrono/chrono,dariomangoni/chrono,Milad-Rakhsha/chrono,PedroTrujilloV/chrono,jcmadsen/chrono,hsu/chrono,jcmadsen/chrono,Bryan-Peterson/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,dariomangoni/chrono,PedroTrujilloV/chrono,tjolsen/chrono,amelmquist/chrono,hsu/chrono,dariomangoni/chrono,PedroTrujilloV/chrono,Milad-Rakhsha/chrono,rserban/chrono,jcmadsen/chrono