tsan: start the background thread with signals blocked, otherwise it can steal users signals



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193519 91177308-0d34-0410-b5e6-96231b3b80d8
asan/msan: separate different report blocks with new lines

this makes the reports consistent with tsan, and much more readable.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193520 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer] Revert r193501 and properly fix r193448

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193522 91177308-0d34-0410-b5e6-96231b3b80d8
[msan] Fix a typo and enable poison_in_free flag.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193529 91177308-0d34-0410-b5e6-96231b3b80d8
[msan] Intercept shmat.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193581 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer] Simplify StackTrace::PrintStack interface: prefer common flags to turn on/off the symbolization

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@193587 91177308-0d34-0410-b5e6-96231b3b80d8