oasis quickstart
fix _oasis
generate files
add ppt
add src
add test
ignore
test case
add arch
add TODO
add llvm
add README
change suffix for llvm
upadte author field
support ConstValue, ArithmeticOperator, FunDef, FunCall
disable all optimization
support external funciton call
add exteranl function
refactor virtual
support ifeq