Merging r340751:

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r340751 | hans | 2018-08-27 17:55:39 +0200 (Mon, 27 Aug 2018) | 7 lines

Use a lambda for calls to ::open in RetryAfterSignal

In Bionic, open can be overloaded for _FORTIFY_SOURCE support, causing
compile errors of RetryAfterSignal due to overload resolution. Wrapping
the call in a lambda avoids this.

Based on a patch by Chih-Wei Huang <cwhuang@linux.org.tw>!
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@341044 91177308-0d34-0410-b5e6-96231b3b80d8