x >=u x >> y
x >=u x udiv y
Summary: Extends InstSimplify to handle both `x >=u x >> y` and `x >=u x udiv y`. This is a folloup of rL258422 and https://github.com/rust-lang/rust/pull/30917 where llvm failed to optimize away the bounds checking in a binary search. Patch by Arthur Silva! Reviewers: sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D25941 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285228 91177308-0d34-0410-b5e6-96231b3b80d8
