tsan: always subtract one from program counters
tsan: always subtract one from program counters

Go has a pending change to pass proper PCs to tsan:
https://go-review.googlesource.com/#/c/4902/
So now we can always subtract one from PCs.



git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@229262 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt