[Msan] Fix some interceptors to pass initialization on FreeBSD
Differential Revision: http://reviews.llvm.org/D6417


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@222885 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] Remove the local copy of Android ucontext.h.

This header is present in the r10c release of the NDK.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@222915 91177308-0d34-0410-b5e6-96231b3b80d8