proc.c: rb_block_min_max_arity

	* proc.c (rb_block_min_max_arity): new function to get arity range
	  from the current block.
	vm_eval.c: rb_lambda_call

	* enum.c (enum_collect): make the block arity same as the given
	  block.  [Bug #13391]

	* internal.h (vm_ifunc): store arity instead of unused id.

	* proc.c (rb_vm_block_min_max_arity): return ifunc arity.

	* vm_eval.c (rb_lambda_call): call method with lambda block.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59500 b2dd03c8-39d4-4d8f-98ff-823fe69b080e