Include errno.h to fix compile errors in gcc 3.4
Include errno.h to fix compile errors in gcc 3.4

sim/main.cc:
    Include errno.h

--HG--
extra : convert_revision : ff91579ae590b3c1d11f7468b71f295e6f3edd68

rjschof/gem5,joerocklin/gem5,qizenguf/MLC-STT,aclifton/cpeg853-gem5,zlfben/gem5,TUD-OS/gem5-dtu,SanchayanMaity/gem5,zlfben/gem5,yb-kim/gemV,sobercoder/gem5,markoshorro/gem5,Weil0ng/gem5,briancoutinho0905/2dsampling,gem5/gem5,sobercoder/gem5,rjschof/gem5,austinharris/gem5-riscv,yb-kim/gemV,sobercoder/gem5,powerjg/gem5-ci-test,yb-kim/gemV,rallylee/gem5,powerjg/gem5-ci-test,sobercoder/gem5,zlfben/gem5,SanchayanMaity/gem5,rallylee/gem5,rjschof/gem5,kaiyuanl/gem5,briancoutinho0905/2dsampling,kaiyuanl/gem5,KuroeKurose/gem5,rallylee/gem5,powerjg/gem5-ci-test,KuroeKurose/gem5,qizenguf/MLC-STT,aclifton/cpeg853-gem5,samueldotj/TeeRISC-Simulator,HwisooSo/gemV-update,aclifton/cpeg853-gem5,briancoutinho0905/2dsampling,TUD-OS/gem5-dtu,powerjg/gem5-ci-test,yb-kim/gemV,zlfben/gem5,markoshorro/gem5,rjschof/gem5,gedare/gem5,austinharris/gem5-riscv,HwisooSo/gemV-update,cancro7/gem5,gedare/gem5,cancro7/gem5,qizenguf/MLC-STT,SanchayanMaity/gem5,markoshorro/gem5,yb-kim/gemV,kaiyuanl/gem5,kaiyuanl/gem5,kaiyuanl/gem5,samueldotj/TeeRISC-Simulator,qizenguf/MLC-STT,rjschof/gem5,briancoutinho0905/2dsampling,rjschof/gem5,sobercoder/gem5,gem5/gem5,TUD-OS/gem5-dtu,Weil0ng/gem5,austinharris/gem5-riscv,gem5/gem5,cancro7/gem5,zlfben/gem5,powerjg/gem5-ci-test,KuroeKurose/gem5,joerocklin/gem5,cancro7/gem5,joerocklin/gem5,qizenguf/MLC-STT,rallylee/gem5,gedare/gem5,powerjg/gem5-ci-test,SanchayanMaity/gem5,aclifton/cpeg853-gem5,HwisooSo/gemV-update,TUD-OS/gem5-dtu,HwisooSo/gemV-update,SanchayanMaity/gem5,joerocklin/gem5,joerocklin/gem5,gedare/gem5,briancoutinho0905/2dsampling,gem5/gem5,markoshorro/gem5,rallylee/gem5,gedare/gem5,TUD-OS/gem5-dtu,gem5/gem5,kaiyuanl/gem5,gedare/gem5,yb-kim/gemV,zlfben/gem5,gedare/gem5,HwisooSo/gemV-update,KuroeKurose/gem5,markoshorro/gem5,rallylee/gem5,samueldotj/TeeRISC-Simulator,samueldotj/TeeRISC-Simulator,markoshorro/gem5,sobercoder/gem5,gem5/gem5,Weil0ng/gem5,aclifton/cpeg853-gem5,yb-kim/gemV,Weil0ng/gem5,zlfben/gem5,joerocklin/gem5,powerjg/gem5-ci-test,markoshorro/gem5,joerocklin/gem5,cancro7/gem5,TUD-OS/gem5-dtu,gem5/gem5,SanchayanMaity/gem5,rjschof/gem5,aclifton/cpeg853-gem5,Weil0ng/gem5,rallylee/gem5,qizenguf/MLC-STT,SanchayanMaity/gem5,austinharris/gem5-riscv,KuroeKurose/gem5,yb-kim/gemV,aclifton/cpeg853-gem5,KuroeKurose/gem5,qizenguf/MLC-STT,HwisooSo/gemV-update,samueldotj/TeeRISC-Simulator,austinharris/gem5-riscv,briancoutinho0905/2dsampling,austinharris/gem5-riscv,cancro7/gem5,samueldotj/TeeRISC-Simulator,briancoutinho0905/2dsampling,HwisooSo/gemV-update,cancro7/gem5,sobercoder/gem5,Weil0ng/gem5,samueldotj/TeeRISC-Simulator,KuroeKurose/gem5,TUD-OS/gem5-dtu,joerocklin/gem5,austinharris/gem5-riscv,kaiyuanl/gem5,Weil0ng/gem5