Shared AOT cache: Support git deps

fixed https://github.com/clojure/clojurescript/commit/e2310802e212cb0e33fead6dbb40bc1972f82012

CLJS-2651-4.patch rebaselines.

CLJS-2651-3.patch rebaselines

CLJS-2651-2.patch rebaselines

The attached patch factors out some of the JAR-based caching logic for reuse.

It copies about 7 lines of code from clojure.tools.gitlibs instead of taking on a dep, for the purposes of identifying the users .gitlibs directory.

Otherwise the patch is fairly straightworward: If the file being compiled is a gitlibs file, it will put the compiled output in the cache if not already there, and likewise if not in the output directory, it will copy from the cache.

I tested the patch manually using core.async:

deps.edn

Then (require 'clojure.core.async).

Note that files are compiled from the git dep location to the shared AOT cache and then copied to the out dir

Stop and restart REPL.

Then (require 'clojure.core.async)

This will exhibit normal quick startup owing to out being populated.

Stop REPL.
Now remove the out dir.
Start REPL:

Then (require 'clojure.core.async).

Note that cached files will now be copied as expected

Additionally, if you then revise deps.edn to depend on the core.async shipping JAR, stop REPL and restart and require core async, things will be recompiled in out as needed. The same thing will happen when you switch back to the git dep.