[sanitizer] Fix build with older kernels.

PTRACE_SETREGSET & PTRACE_GETREGSET may be missing from linux headers.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@185317 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] Add sanity test for asan_symbolize.py script

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@185318 91177308-0d34-0410-b5e6-96231b3b80d8