clover/llvm: Use device in llvm compilation instead of copying fields

clover/llvm: Use device in llvm compilation instead of copying fields

Copying the individual fields from the device when compiling/linking
will lead to an unnecessarily large number of fields getting passed
around.

v3: Rebase on current master
v2: Use device in function args before making additional changes in
    following patches

Signed-off-by: Aaron Watry <awatry@gmail.com>
Reviewed-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-by: Pierre Moreau <pierre.morrow@free.fr>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>