SOLARIS: save kernel module function arguments for debugging

SOLARIS: save kernel module function arguments for debugging

Add the -Wu,-save_args compiler option when building kernel modules
under Solaris 10 and 11 for the amd64 architecture.

Binaries generated with this option save function arguments on the stack
during function entry for debugging purposes. Up to six integer
arguments are saved on function entry, and are not modified during the
execution of the function.

[mmeffie: commit message update]

Change-Id: I7ee50e5108a46685efa17d0380883c6d1702a5e4
Reviewed-on: https://gerrit.openafs.org/12798
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>