[ASan] Add DLL thunks for the new stack UAR interface

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@191188 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] Fix a compile-time warning

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@191189 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan/Win] Slightly optimize the DLL thunk

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@191190 91177308-0d34-0410-b5e6-96231b3b80d8