re PR c++/81327 (cast to void* does not suppress -Wclass-memaccess)

re PR c++/81327 (cast to void* does not suppress -Wclass-memaccess)

	PR c++/81327
	* call.c (maybe_warn_class_memaccess): Add forward declaration.
	Change last argument from tree * to const vec<tree, va_gc> *, adjust
	args uses and check number of operands too.  Don't strip away any
	nops.  Use maybe_constant_value when looking for INTEGER_CST args.
	Deal with src argument not having pointer type.  Check
	tree_fits_uhwi_p before calling tree_to_uhwi.  Remove useless
	test.
	(build_over_call): Call maybe_warn_class_memaccess here on the
	original arguments.
	(build_cxx_call): Rather than here on converted arguments.

	* g++.dg/Wclass-memaccess-2.C: Don't expect a warning when explicitly
	cast to void *.

From-SVN: r256440