add ssa_afl_fuzzer, export SSA parser and interpreter

[michaeljklein]

Description

Problem*

It's hard to write a valid-input-AST generator while also generating counterintuitive SSA programs.

Summary*

#8407 is focused on modifying the existing ssa_fuzzer while this PR is focused on a new afl.rs fuzzer using the SSA interpreter.

1. I was able to avoid writing a valid-input-AST generator by using the following to filter afl.rs-detected crashes:

• std::process::exit(0) to filter invalid-input errors
• The stacker crate to filter out stack overflow errors

2. I found test cases for the defunctionalize SSA pass using this fuzzer: chore(test): add panicking tests for 'defunctionalize' #8510

Additional Context

• I based this off of sn/ssa_fuzzer_branching, which was WIP when I started, to get the latest support for CFG-related instructions
• Renamed from afl_ssa_fuzzer_branching
• afl.rs docs
• I think that std::process::exit(0)'s should only be enabled when a fuzzing-specific cfg feature is enabled

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.