Document an anomaly in this testcase.
Document an anomaly in this testcase.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@262264 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 692e80bd5c8c48811fc948d44e22e7f03bbbb82d)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm