Merging r313278:

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r313278 | prazek | 2017-09-14 10:33:08 -0700 (Thu, 14 Sep 2017) | 11 lines

Enable __declspec(selectany) on any platform

Summary:
This feature was disabled probably by mistake in rL300562
This fixes bug https://bugs.llvm.org/show_bug.cgi?id=33285

Reviewers: davide, rnk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33852
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llvm-svn: 318133