Merging r284110:

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r284110 | abataev | 2016-10-13 09:52:46 +0000 (Thu, 13 Oct 2016) | 9 lines

Fix for PR30639: CGDebugInfo Null dereference with OpenMP array
access, by Erich Keane

OpenMP creates a variable array type with a a null size-expr. The Debug
generation failed to due to this. This patch corrects the openmp
implementation, updates the tests, and adds a new one for this
condition.

Differential Revision: https://reviews.llvm.org/D25373
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_39@286964 91177308-0d34-0410-b5e6-96231b3b80d8