Allow FUZZING_ENGINE=fsanitize_fuzzer for fresh clang
Allow FUZZING_ENGINE=fsanitize_fuzzer for fresh clang

google/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,dnoursi/fuzzer-test-suite,google/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,dnoursi/fuzzer-test-suite,google/fuzzer-test-suite