AFLGo Link-Time Instrumentation

include/Fuzzing/AFLGoLinker/ and lib/Fuzzing/AFLGoLinker/ implement the link-time instrumentation passes for AFLGo-style directed fuzzing.

Location: include/Fuzzing/AFLGoLinker/, lib/Fuzzing/AFLGoLinker/

Build Status: Source retained; the subdirectory is commented out as TBD in lib/Fuzzing/CMakeLists.txt and not included in default builds.

Main passes:

AFLGoDistanceInstrumentationPass instruments distance feedback.
FunctionDistancePass injects function-level distance data.
DAFLInstrumentationPass adds DAFL-specific instrumentation.
DuplicateTargetRemovalPass and AFLGoTargetInjectionFixupPass clean up target metadata before final code generation.

Role in the pipeline:

consume the analyses from Directed Fuzzing Analyses
insert profile-guiding feedback at LTO time
finalize target handling for directed greybox fuzzers

Operational notes

Use the linker passes with the distance and target facts generated for the same program revision. The cleanup passes run before final code generation so instrumentation observes a consistent set of target annotations. Validate the resulting bitcode or executable with a small corpus before interpreting distance feedback as a fuzzing-quality signal.