Build system support for a library having more than one init/fini symbol

Build system support for a library having more than one init/fini symbol
defined, when using linker options to specify these functions.  Now
LIBINITFUNC/LIBFINIFUNC are considered lists of symbols, ordered from
lowest-level (init run first, fini run last) to highest-level.

* lib.in (config.status): Change target to be in $thisconfigdir rather than
local.
(osf1.exports): Create a temporary file then rename into place.  Add options
for library init/fini symbols, handling multiple values.

* shlib.conf (case alpha*-dec-osf*): Don't handle init/fini symbols here.
(case mips-sgi-irix*): Handle multiple init/fini symbols.  Always set $initfini
before it gets used.
(case *-*-solaris*, not gcc): Handle multiple init/fini symbols.
(case *-*-aix*): Handle multiple fini symbols.

ticket: 2916
status: open

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@17088 dc483132-0cff-0310-8789-dd5450dbe970