tsan: improve error message for Go



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@200914 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: remove unused functions



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@200915 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: simplify Go build script
we don't use assembly files



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@200916 91177308-0d34-0410-b5e6-96231b3b80d8