Fix callee type generation (#186272)
The callee_type metadata is expected to be a list of generalized type
metadata by the IR verifier. But for indirect calls with internal
linkage the type metadata is just an integer. Avoid including them in
callee_type metadata.
This will reduce the precision of the generated call graph as the edges to internal linkage functions whose address were taken will not be present anymore. We need to handle this in the future.
