[asan] Fix a deadlock between asan's allocator and lsan

Summary:
This fixes a deadlock which happens in lsan
on a large memalign-allocated chunk that resides in lsan's root set.

Reviewers: samsonov, earthdok

Reviewed By: earthdok

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1957

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192885 91177308-0d34-0410-b5e6-96231b3b80d8