[Sanitizer] Workaround for -Wunused-private-field warning - add an attribute in TSan unit test, and silence this warning as gtest has unused fields.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@158449 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed