these can never be null.
mark unused function as used.
PR/34796: Hauke Fath: ftp does not timeout on http fetches.
Tag liblto_plugin.so.0.0.debug with gcc=48.
PR/48098: Brian Marcotte: panic: kernel diagnostic assertion "cred != NULL":
Fix from Michael van Elst, tcpdrop crashes kernel on ebryonic connections.
_g libraries don't belong here.
Fix debuglib entries
one more debuglib
fix old style decls
mark some variables as unused, but keep them around as comments
make a gcc unitialized variable
sprinkle vax
move unused code inside if 0
more unused inside 0
move unused variable inside if 0
use __USE() in the iterator variable
cleanvnode():
- VC_XLOCK/VC_MASK are not used anymore, remove.
- If we get a reference while cleaning, there is no need to retry as
  these reference and this vnode will disappear soon.
- Make sure we run inside a fstrans transaction to prevent deadlocks
  against vget().

vrecycle():
- don't even try to recycle a vnode currently cleaning.
let progressmeter deal with the timeout once we've started transferring.
- apply some __diagused
- remove unused variables
- move some variables inside their relevant use #ifdef
gcc 4.8.1 wants:
- remove some set but unused variables
- move some variables inside their usage #ifdef's
- cast to (void) instead of using a dummy return variable

(there are more to come, but this one is now tested with gcc 4.5)