replace LeakSanitizerIsTurnedOffForTheCurrentProcess with __lsan_is_turned_off, but this time hide it under __has_feature(address_sanitizer); also include <sanitizer/lsan_interface.h>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199303 91177308-0d34-0410-b5e6-96231b3b80d8