Describe Compiler explorer usage

in src/Debugging.md

@wsmoses Do you have the flag at hand in the compiler explorer (opt-17) to analyze a specific function? I want to add it to the docs here and I couldn't find it in enzyme core docs. The flags from the test don't seem to have an effect in the explorer.
e.g. `-passes="print-type-analysis" -type-analysis-func=asdf` compiles fine even if asdf doesn't exist (and doesn't do anything if asdf exists either). I remember they were slightly different online, but I can't remember how.