Remove some code

[kpamnany]

Merge only with mmtk/julia#5.

• Correct prototype for run_finalizer.
• Remove jl_mmtk_gc_alloc_default_llvm, no longer needed.
• Remove calls to gc_time_mallocd_array_*, only needed with GC_TIME.
• Remove call to verify_parent1, only needed with GC_VERIFY.

[qinsoon]

The test failure in build-test-stdlib seems unrelated. We also saw it with other PRs. It seems to be a network issue in the Julia tests. The ccall test failure could be related with this PR (https://github.com/mmtk/mmtk-julia/actions/runs/4410644810/jobs/7728326632)

    JULIA test/ccall
Running parallel tests with:
  nworkers() = 1
  nthreads() = 1
  Sys.CPU_THREADS = 2
  Sys.total_memory() = 6.787 GiB
  Sys.free_memory() = 5.601 GiB

Test  (Worker) | Time (s) | GC (s) | GC % | Alloc (MB) | RSS (MB)
ccall      (1) |        started at 2023-03-14T00:59:52.698
thread '<unnamed>' panicked at 'MMTk collection has been initialized (was initialize_collection() already called before?)', /home/runner/.cargo/git/checkouts/mmtk-core-3306bdeb8eb4322b/08fd8ab/src/memory_manager.rs:459:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5

Is the code path related with initialize_collection called multiple times after refactoring?

[kpamnany]

Is the code path related with initialize_collection called multiple times after refactoring?

I hadn't thought that would be possible; studying it now.

[kpamnany]

Pushed a commit that should fix the call path to initialize_collection here.