Implemented erlang:bump_reductions nif.

[FKubisSWM]

These changes are made under both the "Apache 2.0" and the "GNU Lesser General Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

[FKubisSWM]

I agree with @pguyot, this change is going to slow down the interpreter.

I suggest to stub this nif (and leaving a TODO) and to implement in a more efficient way this later. Also, in general might be useful to allow some expensive NIFs to burn more than just one reduction (or maybe to restore them).

However the only information I found about this function is:

This BIF can be removed in a future version of the Beam machine without prior warning. It is unlikely to be implemented in other Erlang implementations. Here: https://www.erlang.org/docs/19/man/erlang#bump_reductions-1

So should I leave only a TODO comment (in erlang.erl) or should I make some dummy implementation like for example:

-spec bump_reductions(pos_integer()) -> true.
bump_reductions(Reductions) when is_integer(Reductions), Reductions >= 1 ->
    bump_reductions(Reductions-1);
bump_reductions(0) ->
    true.

[FKubisSWM]

Also, we need the bump_reductions function for context switching testing purposes.

[jgonet]

Also, we need the bump_reductions function for context switching testing purposes.

To expand on that: I thought I used it somewhere in ETS for testing but I can't find a reference to that. The more important thing is that prim_eval (used in erl_eval) uses it. I think we can go with a mock or we can patch it ourselves in the Popcorn since this is internal function and not part of public API.

I still think it may be useful in testing but it should be implemented in a way that doesn't slow down AtomVM in release builds.