XCore target has -fno-use-cxa-atexit as default.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@194460 91177308-0d34-0410-b5e6-96231b3b80d8
XCore target Type defines.

Change SizeType, PtrDiffType, IntPtrType, WCharType, WIntType
to follow the XMOS llvm-gcc front end's settings.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@194461 91177308-0d34-0410-b5e6-96231b3b80d8
XCore target requires preferred alignment.

The xcore llvm backend does not handle 8 byte alignment viz:
  "%BadAlignment = alloca i64, align 8"
So getPreferredTypeAlign() must never overalign.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@194462 91177308-0d34-0410-b5e6-96231b3b80d8