Add DEBUGFLAGS for opt command to control -debug
Prefer the DEBUG macro to std::cout
DynValue/DynBasicBloc is class instead of struct

They were structs which are actually classes. We prefer the class
keyword in order to avoid the warnings.
Remove -Wformat warnings
Disable warning use -Wno-deprecated.
Delete or comment unused functions and variables

Now this version can be compiled by clang/clang++ without any warning.