library. As the value suggests, this allows the library to be built repeatably;
without this flag, gcc uses a random value in its parsing.
Since the random seed is only used when handling files which do not have any
externally-visible symbols, this change is not needed for any other libraries
in the FreeBSD base system.
Discussed on: freebsd-arch (in early November)
Approved by: kan
MFC after: 1 week
08df008505