Unit tests today perform a series of setup steps when initiating a unit test binary.

These include initializing the globally registered initializers as well as initializing the TestingProctor.

However, fuzztests that use existing unit test fixtures have to manually setup the initializers themselves as there is no such initialization done for them. Otherwise they might not start up due to having uninitialized global variables.

An example of this is the Sharding DDL fuzzer added in SERVER-129228.