mozilla/rust — pull request #14710 by alexcrichton (2014-06-07 01:05:21+00:00)
Title: rustc: Preserve reachable extern fns with LTO

All rust functions are internal implementation details with respect to the ABI
exposed by crates, but extern fns are public components of the ABI and shouldn't
be stripped. This commit serializes reachable extern fns to metadata, so when
LTO is performed all of their symbols are not stripped.