Did not update the result from `mrb_check_string_type()` before
string-to-integer conversion.

The fix for #3539 was incomplete.

GC may be called with OP_ENTER (especially when GC_STRESS is set).

VM stack is cleared by 5c114c91, 0cb501 and c063641a.

Otherwise, the following script prints an uninitialized value.

def f(*a)
  if false
    b = 15
  end
  p b
end
f(1,2,3)

Attach a name to  embbeded value of rescue/ensure stack size

Get constant of parent class even if child class is defined in signle…

ref #3588

Correctly handle large negative usec value.

Change AppVeyor's clone_depth

This reverts commit 6dabb336.

Change return value of Enumerable#each_slice