Allow load-immediates to be rematerialised in the register coalescer for
PPC. This makes test/CodeGen/PowerPC/big-endian-formal-args.ll fail,
because it relies on a register move getting emitted. The immediate load is
equivalent, so change this test case.
Patch by Tobias von Koch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162727 91177308-0d34-0410-b5e6-96231b3b80d8
