[sanitizer][NFC] Set LargeMmapAllocator type from PrimaryAllocator

They need to have same AddressSpaceView and MapUnmapCallback.

Reviewers: eugenis

Subscribers: kubamracek, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D61168

llvm-svn: 359719