[WebAssembly] Saturating arithmetic intrinsics

Summary: Depends on D52805.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52813

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343833 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed