0.6.4

0.6.3

allocated * 2 and it seems work well

heap size = 0x8000

heap size = 0x8000

fix: change RuntimeFlags::ZOMBIE(usize) to RuntimeFlags::ZOMBIE(isize), because exit code should be signed number

refactor: merge stop_current_and_run_next, exit_..._next and block_..._next into one function: schedule

fix: disable some test functions, add new test function for SYSCALL_OPEN in user/lib/src/bin/test_fs