mrb_check_convert_type should always return nil on error
stack pos should be adjusted for CFUNC OP_EXEC
keep minimal stack space (recv and blk)
wrong return value from empty block/lambda
small return optimization: use R0 to set return value if possible
Time.new may not take any argument
mrb_get_args("&") gave wrong value
use mrb_obj_equal to check pool
struct.c refactoring
update regs after cfunc call
update regs after cfunc call [2]
Fix a memory leak in mrb_realloc().
Merge pull request #414 from monaka/pr-fix-memory-reak-in-mrb_realloc

Fix a memory leak in mrb_realloc().
mrb_define_method_vm should update target_class
mrb_singleton_class should raise TypeError for immediate objects
define_method to copy block body
super look-up scheme fixed; close #415
load_exec(): Fix message lenghtes in mrb_exc_new().
mrb_run(): Fix not to use a magic number but sizeof.
Merge pull request #416 from monaka/pr-fix-message-length

Fix message lengths.
remove OP_MOVE just before OP_RETURN