Apple defines MAP_ANON, not MAP_ANONYMOUS
Apple defines MAP_ANON, not MAP_ANONYMOUS

Summary:
- Linux considers MAP_ANON deprecated, but it's all that Apple defines.
Manually set up a mapping of one to the other.

Test Plan:
- fbconfig -r folly && fbmake runtests
- ./configure && make check on Ubuntu/FC/Mac

Reviewed By: mwang@fb.com

FB internal diff: D998511

arg0/folly,chjp2046/folly,loversInJapan/folly,clearlylin/folly,bowlofstew/folly,fw1121/folly,arg0/folly,floxard/folly,juniway/folly,loverszhaokai/folly,doctaweeks/folly,rklabs/folly,CJstar/folly,romange/folly,loverszhaokai/folly,Eagle-X/folly,SammyK/folly,sonnyhu/folly,tomhughes/folly,clearlinux/folly,loverszhaokai/folly,yangjin-unique/folly,bikong2/folly,sakishum/folly,cppfool/folly,ykarlsbrun/folly,stonegithubs/folly,SeanRBurton/folly,bsampath/folly,loverszhaokai/folly,wildinto/folly,charsyam/folly,nickhen/folly,KSreeHarsha/folly,arg0/folly,bsampath/folly,hongliangzhao/folly,wildinto/folly,CJstar/folly,facebook/folly,colemancda/folly,arg0/folly,cole14/folly,bobegir/folly,upsoft/folly,alexst07/folly,tempbottle/folly,CJstar/folly,bowlofstew/folly,bowlofstew/folly,Orvid/folly,facebook/folly,xzmagic/folly,leolujuyi/folly,facebook/folly,yangjin-unique/folly,xzmagic/folly,gavioto/folly,Orvid/folly,sonnyhu/folly,colemancda/folly,KSreeHarsha/folly,reddit/folly,kernelim/folly,cole14/folly,wildinto/folly,zhiweicai/folly,SammyK/folly,floxard/folly,gaoyingie/folly,project-zerus/folly,renyinew/folly,renyinew/folly,hongliangzhao/folly,bsampath/folly,cole14/folly,tomhughes/folly,chjp2046/folly,tempbottle/folly,yangjin-unique/folly,brunomorishita/folly,hongliangzhao/folly,PPC64/folly,tempbottle/folly,fw1121/folly,renyinew/folly,project-zerus/folly,Hincoin/folly,bobegir/folly,kernelim/folly,unmeshvrije/C--,arg0/folly,alexst07/folly,gavioto/folly,PoisonBOx/folly,constantine001/folly,Orvid/folly,clearlinux/folly,SeanRBurton/folly,sonnyhu/folly,guker/folly,xzmagic/folly,loversInJapan/folly,guker/folly,alexst07/folly,bobegir/folly,colemancda/folly,nickhen/folly,leolujuyi/folly,reddit/folly,bsampath/folly,loverszhaokai/folly,colemancda/folly,gavioto/folly,bikong2/folly,tomhughes/folly,juniway/folly,ykarlsbrun/folly,hongliangzhao/folly,bobegir/folly,Hincoin/folly,PoisonBOx/folly,loversInJapan/folly,floxard/folly,stonegithubs/folly,sakishum/folly,theiver9827/folly,leolujuyi/folly,unmeshvrije/C--,Eagle-X/folly,bikong2/folly,theiver9827/folly,lifei/folly,PPC64/folly,xzmagic/folly,Orvid/folly,stonegithubs/folly,shaobz/folly,xzmagic/folly,shaobz/folly,theiver9827/folly,tempbottle/folly,ykarlsbrun/folly,PoisonBOx/folly,unmeshvrije/C--,charsyam/folly,project-zerus/folly,upsoft/folly,sonnyhu/folly,leolujuyi/folly,floxard/folly,cppfool/folly,SammyK/folly,yangjin-unique/folly,alexst07/folly,theiver9827/folly,floxard/folly,ykarlsbrun/folly,bikong2/folly,doctaweeks/folly,SammyK/folly,yangjin-unique/folly,Hincoin/folly,shaobz/folly,bobegir/folly,nickhen/folly,shaobz/folly,brunomorishita/folly,chjp2046/folly,kernelim/folly,hongliangzhao/folly,gaoyingie/folly,fw1121/folly,reddit/folly,cppfool/folly,gavioto/folly,fw1121/folly,romange/folly,project-zerus/folly,bowlofstew/folly,lifei/folly,alexst07/folly,Orvid/folly,renyinew/folly,facebook/folly,chjp2046/folly,brunomorishita/folly,clearlylin/folly,raphaelamorim/folly,cole14/folly,wildinto/folly,guker/folly,clearlylin/folly,cppfool/folly,romange/folly,upsoft/folly,project-zerus/folly,CJstar/folly,Eagle-X/folly,PPC64/folly,rklabs/folly,charsyam/folly,upsoft/folly,sakishum/folly,reddit/folly,doctaweeks/folly,doctaweeks/folly,juniway/folly,reddit/folly,tempbottle/folly,SeanRBurton/folly,stonegithubs/folly,cppfool/folly,zhiweicai/folly,charsyam/folly,SeanRBurton/folly,romange/folly,nickhen/folly,mqeizi/folly,wildinto/folly,romange/folly,loversInJapan/folly,gaoyingie/folly,raphaelamorim/folly,sakishum/folly,PoisonBOx/folly,rklabs/folly,constantine001/folly,mqeizi/folly,leolujuyi/folly,cole14/folly,juniway/folly,nickhen/folly,facebook/folly,brunomorishita/folly,sonnyhu/folly,kernelim/folly,tomhughes/folly,rklabs/folly,bikong2/folly,clearlylin/folly,Eagle-X/folly,constantine001/folly,PPC64/folly,theiver9827/folly,loversInJapan/folly,constantine001/folly,Eagle-X/folly,shaobz/folly,unmeshvrije/C--,doctaweeks/folly,guker/folly,lifei/folly,renyinew/folly,raphaelamorim/folly,clearlinux/folly,chjp2046/folly,raphaelamorim/folly,unmeshvrije/C--,upsoft/folly,KSreeHarsha/folly,gaoyingie/folly,clearlinux/folly,gaoyingie/folly,kernelim/folly,clearlinux/folly,mqeizi/folly,CJstar/folly,rklabs/folly,ykarlsbrun/folly,bsampath/folly,stonegithubs/folly,constantine001/folly,fw1121/folly,lifei/folly,juniway/folly,brunomorishita/folly,lifei/folly,PoisonBOx/folly,clearlylin/folly,KSreeHarsha/folly,zhiweicai/folly,sakishum/folly,guker/folly,zhiweicai/folly,KSreeHarsha/folly,zhiweicai/folly,Hincoin/folly,Hincoin/folly,tomhughes/folly,gavioto/folly,unmeshvrije/C--,mqeizi/folly,SeanRBurton/folly,SammyK/folly,PPC64/folly,raphaelamorim/folly,colemancda/folly,mqeizi/folly,bowlofstew/folly