fix evmjit build for llvm3.8
fix evmjit build for llvm3.8

eco/cpp-ethereum,d-das/cpp-ethereum,expanse-org/cpp-expanse,vaporry/webthree-umbrella,eco/cpp-ethereum,joeldo/cpp-ethereum,gluk256/cpp-ethereum,d-das/cpp-ethereum,xeddmc/cpp-ethereum,expanse-org/cpp-expanse,gluk256/cpp-ethereum,karek314/cpp-ethereum,LefterisJP/cpp-ethereum,karek314/cpp-ethereum,gluk256/cpp-ethereum,joeldo/cpp-ethereum,xeddmc/cpp-ethereum,d-das/cpp-ethereum,xeddmc/cpp-ethereum,gluk256/cpp-ethereum,gluk256/cpp-ethereum,expanse-org/cpp-expanse,LefterisJP/cpp-ethereum,LefterisJP/webthree-umbrella,LefterisJP/cpp-ethereum,xeddmc/cpp-ethereum,xeddmc/cpp-ethereum,LefterisJP/cpp-ethereum,d-das/cpp-ethereum,eco/cpp-ethereum,gluk256/cpp-ethereum,joeldo/cpp-ethereum,d-das/cpp-ethereum,programonauta/webthree-umbrella,expanse-org/cpp-expanse,eco/cpp-ethereum,joeldo/cpp-ethereum,programonauta/webthree-umbrella,eco/cpp-ethereum,karek314/cpp-ethereum,arkpar/webthree-umbrella,LefterisJP/webthree-umbrella,expanse-org/cpp-expanse,karek314/cpp-ethereum,joeldo/cpp-ethereum,LefterisJP/cpp-ethereum,LefterisJP/cpp-ethereum,eco/cpp-ethereum,joeldo/cpp-ethereum,karek314/cpp-ethereum,chfast/webthree-umbrella,xeddmc/cpp-ethereum,expanse-org/cpp-expanse,d-das/cpp-ethereum,karek314/cpp-ethereum