tsan: introduce __tsan_default_options() function

The function allows to statically setup default values for flags.
The interafece matches what asan/msan provide.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192715 91177308-0d34-0410-b5e6-96231b3b80d8
[lsan] Fix bug when discovering indirectly leaked objects.

If an object contains pointers to itself, that doesn't make it indirectly
leaked. D'oh!

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192716 91177308-0d34-0410-b5e6-96231b3b80d8