Continuous memory growth in jco component

[ludfjig]

Repeatedly calling an export on one ComponentizeJS instance causes continuous RSS growth and shows no signs of stabilizing. Small repro can be found here https://github.com/ludfjig/jco_leak where the compoentnt exports echo: func(value: list<u8>) -> list<u8>; and is repeatendly called.

With ComponentizeJS 0.22.0:

iteration,rss_mib
0,74.1
10000,266.9
20000,365.4
30000,486.5
40000,611.9
50000,676.1
60000,783.1
70000,898.9
80000,938.0
90000,1056.0
100000,1145.4

Note that ComponentizeJS 0.19.3 does NOT repro the bug as you can see it stabilized on 188.9MiB:

iteration,rss_mib
0,70.2
10000,162.6
20000,188.4
30000,188.8
40000,188.9
50000,188.9
60000,188.9
70000,188.9
80000,188.9
90000,188.9
100000,188.9

I believe the bug was introduced in #319.

Note: I reported a similar bug in #279 and fixed it in #295.