This patch fixes problem with passing structures and unions

smaller than register as argument in variadic functions on
big endian architectures.
Differential Revision: http://reviews.llvm.org/D21611


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273665 91177308-0d34-0410-b5e6-96231b3b80d8