Fix muzzled builds (#5093)

Fix muzzled builds (#5093)

Commit 2c2f05c moved some function
definitions from dump.h to dump.cpp, which is good. However, the
corresponding definitions for muzzled builds weren't moved, so muzzled builds
defined the operator << multiple times. This made our nightly
competition build fail. This commit fixes the issue by moving the
alternative definitions to the source file as well.