Add test for PR24379
Add test for PR24379

The fix for this is in LLVM but it depends on how clang handles the alias
attribute, so add a test to the clang tests to make sure everything works
together as expected.

Differential Revision: http://reviews.llvm.org/D11980


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@244756 91177308-0d34-0410-b5e6-96231b3b80d8

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