[asan] Move __asan_handle_no_return to public header

Heretofore asan_handle_no_return was used only by interceptors,
i.e. code private to the ASan runtime. However, on systems without
interceptors, code like libc++abi is built with -fsanitize=address
itself and should call asan_handle_no_return directly from
__cxa_throw so that no interceptor is required.

Patch by Roland McGrath

Differential Revision: https://reviews.llvm.org/D36811

llvm-svn: 311869