Merging r298179:

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r298179 | niravd | 2017-03-17 20:44:07 -0400 (Fri, 17 Mar 2017) | 7 lines

Make library calls sensitive to regparm module flag (Fixes PR3997).

Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050
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llvm-svn: 304242