Intersecting with a Set type object exhausts memory

[taboege]

The Problem

Intersecting a set object with a set type object leads to out-of-memory error.

Expected Behavior

No overzealous memory consumption. Probably the empty set.

Actual Behavior

MoarVM panic: Memory allocation failed; could not allocate xyz bytes

Steps to Reproduce

$ ulimit -v $((1024*1024)) && perl6 -e 'Set ∩ set(1)'

It doesn't matter if the other set is empty or not.

Suggestion by timotimo++:
https://colabti.org/irclogger/irclogger_log/perl6?date=2018-12-03#l718

Environment

Tested on camelia rakudo-moar 38bc682b0.

[lizmat]

Fixed with 99d94db

[lizmat]

Additional fix with 9f5cc8d , tests added with Raku/roast@771ab61bf4

[taboege]

Thank you!