Fix minor typos in comments.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219632 91177308-0d34-0410-b5e6-96231b3b80d8
Sanitize upcasts and conversion to virtual base.

This change adds UBSan check to upcasts. Namely, when we
perform derived-to-base conversion, we:
1) check that the pointer-to-derived has suitable alignment
   and underlying storage, if this pointer is non-null.
2) if vptr-sanitizer is enabled, and we perform conversion to
   virtual base, we check that pointer-to-derived has a matching vptr.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219642 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: refactor atexit handling
The current handling (manual execution of atexit callbacks)
is overly complex and leads to constant problems due to mutual ordering of callbacks.
Instead simply wrap callbacks into our wrapper to establish
the necessary synchronization.
Fixes issue https://code.google.com/p/thread-sanitizer/issues/detail?id=80



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219675 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] Add fast_unwind_on_check flag.

Allows to specify the unwinder to use for CHECK failures. Previous behaviour
was to use the "fatal" unwinder.
As compiler-rt is built without frame pointers, only the slow unwinder
really makes sense here, and it is the default.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219677 91177308-0d34-0410-b5e6-96231b3b80d8