message: Add REQUIRES: windows to NativePDB/stack_unwinding01.cpp
  The test runs the compiled executable. As such, it can only work on
  windows hosts.
diff: // clang-format off
  -// REQUIRES: lld
  +// REQUIRES: lld, system-windows
  // RUN: %build --compiler=clang-cl --nodefaultlib -o %t.exe -- %s
  // RUN: env LLDB_USE_NATIVE_PDB_READER=1 %lldb -f %t.exe -s \
  