Richard Smith:  This fixes a problem in std::is_constructible for incomplete types, and those types with a user-defined operator,().
Richard Smith:  This fixes a problem in std::is_constructible for incomplete types, and those types with a user-defined operator,().

git-svn-id: 756ef344af921d95d562d9e9f9389127a89a6314@167233 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx