Merging r284444:

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r284444 | beanz | 2016-10-17 17:50:39 -0700 (Mon, 17 Oct 2016) | 4 lines

[CMake] Add missing dependency on intrinsics_gen

COFF/InputFiles.h includes LTOModule.h which transitively relies on Attributes.inc.

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llvm-svn: 288078