Merging r298177:

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r298177 | niravd | 2017-03-17 20:43:39 -0400 (Fri, 17 Mar 2017) | 7 lines

[X86] Add NumRegisterParameters Module Flag.

Reviewers: rnk, mkuper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27051
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llvm-svn: 304294