XCore target: correct test layout

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188663 91177308-0d34-0410-b5e6-96231b3b80d8
XCore target: Add target specific EmitVAArg

This is so aggregates can be passed as var args too.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188664 91177308-0d34-0410-b5e6-96231b3b80d8