Merging r321789:

Merging r321789:
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r321789 | hiraditya | 2018-01-03 23:47:24 -0800 (Wed, 03 Jan 2018) | 8 lines

[GVNHoist] Fix: PR35222 gvn-hoist incorrectly erases load in case of a loop

Reviewers:
    dberlin
    sebpop
    eli.friedman

Differential Revision: https://reviews.llvm.org/D41453
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_60@322558 91177308-0d34-0410-b5e6-96231b3b80d8