[asan] Move *scanf declarations out of mac-only section.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173020 91177308-0d34-0410-b5e6-96231b3b80d8
ASan: build unit tests with -fsanitize-address-zero-base-shadow on Linux and Android

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173021 91177308-0d34-0410-b5e6-96231b3b80d8