re PR c++/12037 (Spurious "statement has no effect" in templates)

re PR c++/12037 (Spurious "statement has no effect" in templates)

cp:
	PR c++/12037
	* cp-tree.h (COMPOUND_EXPR_OVERLOADED): New.
	(build_min_non_dep): Declare.
	* tree.c (build_min): Propagate TREE_SIDE_EFFECTS.
	(build_min_non_dep): New.
	* cvt.c (convert_to_void): Don't explicitly copy
	TREE_SIDE_EFFECTS, TREE_NO_UNUSED_WARNING.
	* call.c (build_new_method_call): Use build_min_non_dep.
	* decl2.c (grok_array_decl): Likewise.
	(build_offset_ref_call_from_tree): Likewise.
	* typeck.c (finish_class_member_access_expr,
	build_x_indirect_ref, build_x_binary_op, build_x_unary_op,
	build_x_conditional_expr, build_x_compound_expr): Likewise.
	(build_static_cast, build_reinterpret_cast,
	build_const_cast): Propagate TREE_SIDE_EFFECTS inside a template.
	* typeck2.c (build_x_arrow): Use build_min_non_dep.
	(build_functional_cast): Propagate TREE_SIDE_EFFECTS inside a
	template.
	* rtti.c (build_dynamic_cast_1): Set DECL_IS_PURE.
	(build_dynamic_cast): Set TREE_SIDE_EFFECTS.
	* pt.c (build_non_dependent_expr): Check COMPOUND_EXPR_OVERLOADED.
testsuite:
	PR c++/12037
	* g++.dg/warn/noeffect4.C: New test.

From-SVN: r71108