https://reviews.llvm.org/D102447 attempted to introduces libMutagen/libclang_rt.mutagen.a as a subset of libFuzzer/libclang_rt.fuzzer.a, and was landed as https://reviews.llvm.org/rGc4a41cd77c15c2905ac74beeec09f8343a65a549.
A bug involving uninitialized function pointers in two unit tests only surfaced on Darwin, leading it to be reverted in https://github.com/llvm/llvm-project/commit/fd0a2f75ff4f25a4759afeb72b42ba1b6ccea93f.
This patch is identical to the previous one, except that it zero-initializes the config struct and properly forwards the function pointers in MutagenInterface::SetUp in tests/MutagenUnittest.cpp.
clang-tidy: warning: do not use 'else' after 'return' [llvm-else-after-return]
not useful