[flow-sensitive] bug fix, simplify ShortCircuitOrNode when of check-cast form
[flow-sensitive] simplify to nullConstant
[flow-sensitive] refactoring, factor out evidence-search
Move CIPrintCompilerName handling into CompileTask::print_compilation_impl

--HG--
extra : rebase_source : 5f2df8d271c8758f48edbf33f1de6deb4a9125ad
fixed assertion in debug VM