[asan] add a new interface function __asan_describe_address, useful for running asan-ified binary under a debugger (e.g. gdb)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@171217 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed