Move endian constant from Host.h to SwapByteOrder.h, prune include Works on this dependency chain: ArrayRef.h -> Hashing.h -> --CUT-- Host.h -> StringMap.h / StringRef.h ArrayRef is very popular, but Host.h is rarely needed. Move the IsBigEndianHost constant to SwapByteOrder.h. Clients of that header are more likely to need it. git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@375316 91177308-0d34-0410-b5e6-96231b3b80d8