[MemorySSA] Fix windows build breakage caused by r278028 (take 2)

r278028: [MemorySSA] Ensure address stability of MemorySSA object.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278041 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed