Update MemorySSA in SimpleLoopUnswitch.

Summary:
Teach SimpleLoopUnswitch to preserve MemorySSA.

Subscribers: sanjoy, jlebar, Prazek, george.burgess.iv, llvm-commits

Differential Revision: https://reviews.llvm.org/D47022

llvm-svn: 348263
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/LIV-loop-condtion.ll b/llvm/test/Transforms/SimpleLoopUnswitch/LIV-loop-condtion.ll
index 03c23da..59c14e9 100644
--- a/llvm/test/Transforms/SimpleLoopUnswitch/LIV-loop-condtion.ll
+++ b/llvm/test/Transforms/SimpleLoopUnswitch/LIV-loop-condtion.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -simple-loop-unswitch -S 2>&1 | FileCheck %s
+; RUN: opt < %s -simple-loop-unswitch -enable-mssa-loop-dependency=true -verify-memoryssa -S 2>&1 | FileCheck %s
 
 ; This is to test trivial loop unswitch only happens when trivial condition
 ; itself is an LIV loop condition (not partial LIV which could occur in and/or).