Implement a profiler for VM execution and GC.

[sisshiki1969]

This PR:

• Implements a profiler for VM execution and the garbage collector. This profiler collects and prints execution time per VM instruction, and a frequency and stopping duration of GC. Using --profile option enables this feature.

  $ cargo run --release examples/fibo.js --profile
  Compiling rapidus v0.1.1
  Finished release [optimized] target(s) in 1m 23s
   Running `target/release/rapidus examples/fibo.js --profile`
  # performance analysis
  total execution time 13484 microsecs  gc time 1288 microsecs
  Inst          total %    ave.time / inst
  PushInt8       8.02 %     219.38 nanosecs
  Add            1.25 %     171.36 nanosecs
  Sub            1.58 %     108.34 nanosecs
  Lt             2.10 %     143.54 nanosecs
  JmpIfFalse     1.65 %     113.08 nanosecs
  Call          48.87 %    3339.68 nanosecs
  Return         8.30 %     567.20 nanosecs
  Pop            0.00 %     218.00 nanosecs
  GetValue      18.68 %     425.65 nanosecs
  # GC performance
  State    count        total time
  Init       300        0.00 millisecs
  Mark      1473        0.00 millisecs
  Sweep      200        0.00 millisecs

• Function id becomes to be generated by Factory as new FunctionId type.
• Some codes using deprecated syntax were fixed.
• The frequency of GC was reduced to 1/100, because the GC consumed too much time previously.
• The dependency on LLVM was removed temporally.

• VM#compile() returns UserFunctionInfo instead of FunctionInfo, and generate module id automatically. This refactoring simplifies the code for VM execution.

  /// before
  let mut vm = vm::vm::VM::new();
  let mut parser = parser::Parser::new("test", text);
  let node = parser.parse_all().unwrap();
  let mut iseq = vec![];
  let main_id = vm.factory.main_func_id();
  let func_info = vm.compile(&node, &mut iseq, true, main_id).unwrap();
  vm.run_global(func_info, iseq).unwrap();
  
  /// after
  let mut vm = vm::vm::VM::new();
  let mut parser = parser::Parser::new("test", text);
  let node = parser.parse_all().unwrap();
  let user_func_info = vm.compile(&node, true).unwrap();
  vm.run_global(user_func_info).unwrap();

Thank you for reading this!

[maekawatoshiki]

It looks a very useful profiler. Thank you:tada: