Fix getting environment variables for sanitizers needs on FreeBSD
Differential Revision: http://reviews.llvm.org/D4229


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212690 91177308-0d34-0410-b5e6-96231b3b80d8
Only use fast stack unwinding for sanitizers failure reports on FreeBSD
Differential Revision: http://reviews.llvm.org/D4420


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212691 91177308-0d34-0410-b5e6-96231b3b80d8
Make sanitizers' interceptors non-weak on FreeBSD
Differential Revision: http://reviews.llvm.org/D4418


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212693 91177308-0d34-0410-b5e6-96231b3b80d8