[Fix #103 and #107] Support variable names starting with underscore
[Fix #103 and #107] Support variable names starting with underscore

hkuplg/fcore,bixuanzju/fcore,hkuplg/fcore,wxzh/fcore,zhiyuanshi/fcore,zhiyuanshi/fcore,wxzh/fcore,wxzh/fcore,hkuplg/fcore,xnning/fcore,bixuanzju/fcore,xnning/fcore,xnning/fcore,zhiyuanshi/fcore,bixuanzju/fcore