refactor: put `aot` module and `compile_sharedlib` function under `mu::vm::testutil` module. Also updated some function calls based on updates in master branch

NOTE: Only fixed hand-written ASMs. Emitted ".s" files still have problems.

Implemented dependency resolution.

now we have 4 passes: fast_inst_sel, fast_reg_alloc, followed
by slow_inst_sel and slow_reg_alloc. This might make the
compilation pipeline more linear