Merging r323515:

Merging r323515:
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r323515 | fhahn | 2018-01-26 11:36:50 +0100 (Fri, 26 Jan 2018) | 7 lines

[CallSiteSplitting] Fix infinite loop when recording conditions.

Fix infinite loop when recording conditions by correctly marking basic
blocks as visited.

Fixes https://bugs.llvm.org/show_bug.cgi?id=36105

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_60@323771 91177308-0d34-0410-b5e6-96231b3b80d8