tsan: add Go build script for freebsd


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211419 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: fix windows build script


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211422 91177308-0d34-0410-b5e6-96231b3b80d8