[Truffle] It is IO.open, not File.open (RDoc misleading).
[Truffle] Kernel#respong_to_missing? is private.
[Truffle] Remove a couple inexistant methods.

* GC.start, not ObjectSpace.start.
* Time.time_s_from_array does not exist on Rubinius.
[Truffle] Add the GC module.
[Truffle] Just use inheritance for static delegation, it is much simpler.
[Truffle] Rename RubyMethod.withNewVisibility to just withVisibility.

* The semantics are better reflected with that name.
[Truffle] #initialize and #method_missing should be private.

* And visibility checking for private with an explicit receiver is always false.
[Truffle] TruffleCompilerExceptionsAreThrown doesn't seem to quite work - workaround.
[Truffle] Restructure the PE tests.
Merge branch 'master' into truffle-head
[Truffle] Use fixed throw compiler exceptions.
Add new fake instr to hold intperpreter state.  This instr is destined to only be instr 0 of the linearized instr list used only by the interpreter.  It removes all remaining IRScope state knowledge from interpreter (not currently hooked up).
Boo. nested closures need unmolested parent scopes based on passes which may replace parent variables with temp vars.  We cannot use this simpler approach and will end up going the original full-clone route.  Commented out cloning in prepareInstructions
[Truffle] Found an unexploded loop on the fastest part of the fast path!
Merge branch 'master' into truffle-head
[Truffle] Fix special visibility for accessors on self

* Such as self.foo=bar and self[foo]=bar
Minor interp tweak + removed dead imports.
Turn off requireFrame opt for now since it is buggy in some scenarios

* Fixes some rubyspec failures when this is enabled.
New direction...InterpreterContext
Fix to missing callsites accessing IRScope directly and not interpreterContext