def _load_global_helpers():
    """
    Execute once to install special symbols into the LLVM symbol table.
    """
    # This is Py_None's real C name
    ll.add_symbol("_Py_NoneStruct", id(None))

    # Add Numba C helper functions
    for c_helpers in (_helperlib.c_helpers, _dynfunc.c_helpers):
        for py_name, c_address in c_helpers.items():
            c_name = "numba_" + py_name
            ll.add_symbol(c_name, c_address)

    # Add all built-in exception classes
    for obj in utils.builtins.__dict__.values():
        if isinstance(obj, type) and issubclass(obj, BaseException):
            ll.add_symbol("PyExc_%s" % (obj.__name__), id(obj))

    Execute once to install special symbols into the LLVM symbol table.
    
numba/core/base.py