fix: false OOB with array.fill in classic-interp and fast-interp

[XeniaLu]

Fixes #4644

[yamt]

doesn't the official spec test cover this very basic case? i guess it should be added...

[XeniaLu]

doesn't the official spec test cover this very basic case? i guess it should be added...

Good point! Indeed it doesn't:

https://github.com/WebAssembly/spec/blob/e1ce46897460b74548c5e96b1530f59ef5b366cf/test/core/gc/array_fill.wast#L61-L68

For an array of size 12, the official spec test only covered:

• offset=13, len=0 ❌
• offset=0, len=13 ❌
• offset=12, len=0 ✅
• offset=2, len=2 ✅

I'll add a 3 ones there:

• offset=0, len=12 ✅
• offset=0, len=1 ✅
• offset=8, len=4 ✅