target-def.h (TARGET_CXX_CDTOR_RETURNS_THIS): Define.

target-def.h (TARGET_CXX_CDTOR_RETURNS_THIS): Define.

gcc/
	* target-def.h (TARGET_CXX_CDTOR_RETURNS_THIS): Define.
	(TARGET_CXX): Use it.
	* target.h (struct gcc_target): Add cdtor_returns_this.
	* config/arm/arm.c (arm_cxx_cdtor_returns_this): New function.
	(TARGET_CXX_CDTOR_RETURNS_THIS): Define.
	* doc/tm.texi: Document TARGET_CXX_CDTOR_RETURNS_THIS.
gcc/cp/
	* Make-lang.in (cp/semantics.o, cp/optimize.o): Depend on TARGET_H.
	* cp-tree.h (struct language_function): Rename x_dtor_label to
	x_cdtor_label.
	(dtor_label): Rename ...
	(cdtor_label): ... to this.
	* decl.c (begin_constructor_body): Remove.
	(check_special_function_return_type): Maybe change the return type.
	(grokdeclarator): Pass the class type.
	(start_preparsed_function): Constructors may need a return label.
	(finish_constructor_body, finish_destructor_body): Set the return
	value.
	(begin_function_body): Don't call begin_constructor_body.
	(finish_function): Don't warn for constructors or destructors.
	(implicitly_declare_fn): Maybe change the return type.
	* optimize.c: Include target.h.
	(maybe_clone_body): Remap the function result.
	* semantics.c: Include target.h.
	(finish_return_stmt): Maybe jump to return label for constructors.

From-SVN: r85561