IRIX 6.x shared build fix-up.

For reference. Note that both cc and gcc support -Wl flag, but we can't
use -Wl,-[not]all with both drivers, because cc rearranges options
passed through -Wl. We can't use -Wl,-all,libcrypto.a,-notall with cc
either, because it refuses to start with "no input" error.