Summary: mingw64 has lots of default libs that libc++ and its test programs should link against. With this patch, cmake now runs successfully with GCC on Windows. Reviewers: mati865, EricWF Subscribers: mgorny, cfe-commits Differential Revision: https://reviews.llvm.org/D31518 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@299144 91177308-0d34-0410-b5e6-96231b3b80d8