Minor: Removed dead arg to call in Helpers
[IR] Some more fixes and FIXMEs to inlining code

* More progress inlining code on bench_method_dispatch.rb

* The next set of crashers in inlining requires fixes to the
  WrappedIRClosure operand to take an explicit self arg so that
  on inlining, the correct (original) self can be passed into
  the block rather than passing the self from the host scope
  into which code got inlined. TO BE DONE.
[IR] Extend WrappedIRClosure to include an explicit self operand

* This fix is required for proper inlining of scopes that contain
  blocks so that the self prior-to-inlining can be passed into
  the block after-inlining into another scope.

* With this fix, bench_method_dispatch.rb runs with -Xir.profile=true
  without crashing. Same for bench_fib_recursive, bench_red_black,
  shootout/meteor, shootout/mandelbrot, bench_richards,
  bench_neural_net, and bench_tictactoe.

* There are still known bugs in the inlining code (search for
  FIXMEs or 'This is buggy' comments in the relevant code), but the
  correctness has moved along far enough to enable profiling and
  inlining on a large enough set of programs without crashing or
  yielding incorrect results.
[IR] Fixed broken build from 8fc3ee3
fix an instanceof check to use the right supertype (Numeric)