As a side effect of going thru Codegen_LLVM, it appears that HexagonOffload is including the standard _argv() and _metadata() functions for the HVX functions; since these get embedded in a data block, they don't ever get dead-stripped and are small-but-useless. It would be nice to tweak codegen to omit them.

EDIT: _argv() is actually needed by halide_hexagoon_run(), but the metadata isn't.