The libbson tests' built-in fuzz test has begun failing occasionally, perhaps especially (or only?) on 32-bit Windows. E.g.:

Assertion failed: child_len >= 5, file C:\data\mci\mongo-c-driver\src\libbson\tests\test-iter.c, line 262

What is the purpose of the test? Do its failures reveal bugs in libbson or in the test? Are its failures becoming more common recently for some reason? Is it more common on 32-bit Windows, and why?