tsan: allow to override OnPrint() callback in Go runtime



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192576 91177308-0d34-0410-b5e6-96231b3b80d8
[msan] Regression test for r192575.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192577 91177308-0d34-0410-b5e6-96231b3b80d8