[asan] Use 1 byte aligned stores to poison shadow memory

Summary: r279379 introduced crash on arm 32bit bot. I suspect this is alignment issue.

Reviewers: eugenis

Subscribers: llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D23762

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279413 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed