Merging r347004:

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r347004 | tstellar | 2018-11-16 00:47:24 +0000 (Fri, 16 Nov 2018) | 4 lines

Re-apply r346985: [ADT] Drop llvm::Optional clang-specific optimization for trivially copyable types

Remove a test case that was added with the optimization we are now
removing.
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llvm-svn: 352582