RISC architectures get their memory operand folding for free.

RISC architectures get their memory operand folding for free.

The only folding these load/store architectures can do is converting COPY into a
load or store, and the target independent part of foldMemoryOperand already
knows how to do that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108099 91177308-0d34-0410-b5e6-96231b3b80d8