A closure passed in a module-level call statement is walked under the
file node (#3124), but its params and locals were never registered for
that walk. A parameter passed on as a call argument then resolved against
the corpus-wide label index and produced an indirect_call to any function
with the same name, including module-private ones in other packages.
Record the closure's bindings in closure_locals_by_body, the same way the
#2568 branch already does for const-assigned closures.
