[sanitizer] Handle TLS sizes for glibc < 2.13; As discussed in http://gcc.gnu.org/PR60038, the hardcoded sizeof(struct thread); patch by Jakub Jelinek

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@200733 91177308-0d34-0410-b5e6-96231b3b80d8