Empty hash table fix in .debug_names reader

The handling of an empty hash table in the .debug_names reader is
slightly wrong.

Currently the code assumes there is always an array of hashes.
However, section 6.1.1.4.5 Hash Lookup Table says:

    The optional hash lookup table immediately follows the list of
    type signatures.

and then:

    The hash lookup table is actually two separate arrays: an array of
    buckets, followed immediately by an array of hashes.

My reading of this is that the hash table as a whole is optional, and
so the hashes will not exist in this case.  (This also makes sense
because the hashes are not useful without the buckets anyway.)

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=25950

0 files changed, 0 insertions, 0 deletions