Avoid unnecessary copies when iterating over dictionaries.

Refs #5246
Improve compatibility with -fvisibility=hidden.

Refs #5246
Avoid unnecessary PLT indirection for internal symbols.

Refs #5246
Further decrease WQ lock contention.

Refs #5246
Avoid using dynamic_pointer_cast when possible.

Refs #5246
Allow common functions to be inlined.

Refs #5246