* vm_insnhelper.c (vm_push_frame): fix stack overflow check codes.
  Stack overflow check should be done *after* pushing a stack frame.
  However, some stack overflow checking codes checked *before*
  pushing a stack frame with iseq->stack_max.
  To solve this problem, add a new parameter `stack_max' to specify
  a possible consuming stack size.
* vm_core.h (CHECK_VM_STACK_OVERFLOW0): add to share the stack overflow
  checking code.
* insns.def: catch up this change.
* vm.c, vm_eval.c: ditto.
* test/ruby/test_exception.rb: add a stack overflow test.
  This code is reported by nobu.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42398 b2dd03c8-39d4-4d8f-98ff-823fe69b080e