tsan: use a different dir for llvm build
build is used as gtest temp build dir, and is cleared during every build



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219783 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: fix false positive related to signals
Write interceptor calls malloc, which causes a false
unsafe-call-in-signal-handler report. See the test.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@219784 91177308-0d34-0410-b5e6-96231b3b80d8