[msan] Fix false positive on dynamic tls.

Use existing DTLS code in sanitizer_tls_get_addr.{h,cc} to unpoison DTLS
blocks both on allocation and deallocation.

https://code.google.com/p/memory-sanitizer/issues/detail?id=44


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211683 91177308-0d34-0410-b5e6-96231b3b80d8
[sanitizer] Fix build on platforms where dtls support is disabled.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211684 91177308-0d34-0410-b5e6-96231b3b80d8
[msan] Fix bad interaction between with-calls mode and chained origin tracking.

Origin history should only be recorded for uninitialized values, because it is
meaningless otherwise. This change moves __msan_chain_origin to the runtime
library side and makes it conditional on the corresponding shadow value.

Previous code was correct, but _very_ inefficient.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211700 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] When iterating over segments on OSX, treat the segments' initial
protection level as their current protection level.
This fixes the UNIMPLEMENTED check that started to fire on OSX after r210649.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211713 91177308-0d34-0410-b5e6-96231b3b80d8