This library provides `LookupSymbol` and `LookupSymbolByAddress`. The latter
needs `GetNumSymbols` support. An object file needs either .hash (DT_HASH) or
.gnu.hash (DT_GNU_HASH). This patch adds DT_GNU_HASH support.

Note: glibc has been supporting DT_GNU_HASH since 2006 and .hash has been quite
obsoleted in the Linux communities.
PiperOrigin-RevId: 648459622
Change-Id: I3aa1274cd4617990844258175715e3be2343afd2