[WebAssembly] Omit no-op adds for non-mem uses of FrameIndex

Differential Revision: http://reviews.llvm.org/D16554

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258872 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed