tsan: add back __tls_get_addr interceptor
tsan: add back __tls_get_addr interceptor

Removal of the interceptor broke libtsan interface in gcc:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68824
Add back a simple interceptor.




git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@258119 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt