Do not emit DW_AT_upper_bound and DW_AT_lower_bound for unbouded array.

Do not emit DW_AT_upper_bound and DW_AT_lower_bound for unbouded array.
If lower bound is more then upper bound then consider it is an unbounded array.
An array is unbounded if non-zero lower bound is same as upper bound.
If lower bound and upper bound are zero than array has one element.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129156 91177308-0d34-0410-b5e6-96231b3b80d8