Strip symbols from release build

Most of these symbols are from autocxx- and cxx-generated code and don't
provide much real value. The Rust code is so extensively inlined in
release builds that the symbols are all but useless anyway. By omitting
them, we save 13% binary size.

Author: tchebb

Cargo.toml

@@ -44,4 +44,5 @@ panic = "abort"
 
 [profile.release]
 panic = "abort"
+strip = "symbols"
 lto = "fat"