c++: Expose cloning form predicates

c++: Expose cloning form predicates

A further adjustment of the function cloning.  Rather than have
copy_fndecl_with_name deduce whether a particular cdtor needs a
vtt_parm and/or has inherited parms to drop, pass that information in
from the caller.  In particular build_cdtor_clones knows when its
building the particular cdtors that might need these.  On the modules
branch I need to clone cdtors before the underlying class information
is necessarily complete.  There build_cdtor_clones is externally
callable to facilitate that.

gcc/cp/
	* class.c (copy_fndecl_with_name): Add additional predicate args, do
	not deduce them locally.
	(copy_operator_fn): Adjust copy_fndecl_with_name call.
	(build_clone): Add vtt and inherited predicate args.  Pass through
	to copy_fndecl_with_name call.
	(build_cdtor_clones): Likewise, pass through to build_clone as
	needed.
	(build_cdtor): Determine vtt and inherited here.
	* cp-tree.h (DECL_NEEDS_CTT_PARM_P): Delete.