Add rb_mod_sys_tmp function and Replace duplicate code

[S-H-GAMELINKS]

Some functions(like a rb_mod_sys_fail and rb_mod_sys_fail_str) has duplicate code.
Add rb_mod_sys_tmp function and replaced these duplicate code.

[nobu]

What does tmp mean?

[S-H-GAMELINKS]

It meant a template for these codes

    rb_extend_object(exc, mod);
    rb_exc_raise(exc);

But, I think rb_mod_sys_fail_tmp is better now.

[nobu]

"Template" for what?

sys_fail comes from "system call failure", I think.
OTOH, this function itself is no longer related with system calls, as the exception made from errno is given as an argument, therefore I don't think sys fits it.
Since the role of this function is to "raise the given exception extended with the given module", a name I though out was rb_mod_exc_raise (mod may not sound nice but could be consistent with other rb_mod_*_fail functions).

[S-H-GAMELINKS]

@nobu
Thanks for your comment.
I cloud understanded these functions role.

I intended to mean template means "cut out common code to some function", but it's badly in this case.

rb_mod_exc_raise is good, I think. I'll rename this function.