WebAssembly: generate load/store

Summary: This handles all load/store operations that WebAssembly defines, and handles those necessary for C++ such as i1. I left a FIXME for outstanding features which aren't required for now.

Reviewers: sunfish

Subscribers: jfb, llvm-commits, dschuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246500 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed