ARM: support struct byval in llvm

We handle struct byval by inserting a pseudo op, which will be expanded to a
loop at ExpandISelPseudos.
A separate patch for clang will be submitted to enable struct byval.

rdar://9877866


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157793 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed