scons: allow override of SWIG binary on command line
scons: allow override of SWIG binary on command line

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