Link STT_GNU_IFUNC into STT_FUNC in executable.

Link STT_GNU_IFUNC into STT_FUNC in executable.

Indirect functions shall have STT_FUNC type in executable dynsym
section. Indeed, a dlsym call following a lazy resolution would pick the
symbol value from the executable dynsym entry. This would contain the
address of the function wanted by the caller of dlsym instead of the
address of the function that would return that address.