[Cygwin] Use -femulated-tls by default since r257718 introduced the new pass.

FIXME: Add more targets to use emutls into clang/test/Driver/emulated-tls.cpp.
FIXME: Add cygwin tests into llvm/test/CodeGen/X86. Working in progress.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257984 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed