Convert lvalue reference type check to general reference type check

In almost all contexts (except for overload resolution rules and expression
semantics), lvalue and rvalue references are equivalent. That means that in all
but these cases we can replace a TYPE_CODE_REF check to a TYPE_IS_REFERENCE
check and, for switch statements, add a case label for a rvalue reference type
next to a case label for an lvalue reference type. This patch does exactly
that.

gdb/ChangeLog

	PR gdb/14441
	* aarch64-tdep.c (aarch64_type_align)
	(aarch64_extract_return_value, aarch64_store_return_value): Change
	lvalue reference type checks to general reference type checks.
	* amd64-tdep.c (amd64_classify): Likewise.
	* amd64-windows-tdep.c (amd64_windows_passed_by_integer_register):
	Likewise.
	* arm-tdep.c (arm_type_align, arm_extract_return_value)
	(arm_store_return_value): Likewise.
	* ax-gdb.c (gen_fetch, gen_cast): Likewise.
	* c-typeprint.c (c_print_type): Likewise.
	* c-varobj.c (adjust_value_for_child_access, c_value_of_variable)
	(cplus_number_of_children, cplus_describe_child): Likewise.
	* compile/compile-c-symbols.c (generate_vla_size): Likewise.
	* completer.c (expression_completer): Likewise.
	* cp-support.c (make_symbol_overload_list_adl_namespace):
	Likewise.
	* darwin-nat-info.c (info_mach_region_command): Likewise.
	* dwarf2loc.c (entry_data_value_coerce_ref)
	(value_of_dwarf_reg_entry): Likewise.
	* eval.c (ptrmath_type_p, evaluate_subexp_standard)
	(evaluate_subexp_for_address, evaluate_subexp_for_sizeof):
	Likewise.
	* findvar.c (extract_typed_address, store_typed_address):
	Likewise.
	* gdbtypes.c (rank_one_type): Likewise.
	* hppa-tdep.c (hppa64_integral_or_pointer_p): Likewise.
	* infcall.c (value_arg_coerce): Likewise.
	* language.c (pointer_type): Likewise.
	* m32c-tdep.c (m32c_reg_arg_type, m32c_m16c_address_to_pointer):
	Likewise.
	* m88k-tdep.c (m88k_integral_or_pointer_p): Likewise.
	* mn10300-tdep.c (mn10300_type_align): Likewise.
	* msp430-tdep.c (msp430_push_dummy_call): Likewise.
	* ppc-sysv-tdep.c (do_ppc_sysv_return_value)
	(ppc64_sysv_abi_push_param, ppc64_sysv_abi_return_value):
	Likewise.
	* printcmd.c (print_formatted, x_command): Likewise.
	* python/py-type.c (typy_get_composite, typy_template_argument):
	Likewise.
	* python/py-value.c (valpy_referenced_value)
	(valpy_get_dynamic_type, value_has_field): Likewise.
	* s390-linux-tdep.c (s390_function_arg_integer): Likewise.
	* sparc-tdep.c (sparc_integral_or_pointer_p): Likewise.
	* sparc64-tdep.c (sparc64_integral_or_pointer_p): Likewise.
	* spu-tdep.c (spu_scalar_value_p): Likewise.
	* symtab.c (lookup_symbol_aux): Likewise.
	* typeprint.c (whatis_exp, print_type_scalar): Likewise.
	* valarith.c (binop_types_user_defined_p, unop_user_defined_p):
	Likewise.
	* valops.c (value_cast_pointers, value_cast)
	(value_reinterpret_cast, value_dynamic_cast, value_addr, typecmp)
	(value_struct_elt, value_struct_elt_bitpos)
	(value_find_oload_method_list, find_overload_match)
	(value_rtti_indirect_type): Likewise.
	* valprint.c (val_print_scalar_type_p, generic_val_print):
	Likewise.
	* value.c (value_actual_type, value_as_address, unpack_long)
	(pack_long, pack_unsigned_long, coerce_ref_if_computed)
	(coerce_ref): Likewise.
	* varobj.c (varobj_get_value_type): Likewise.

gdb/python/py-type.c

@@ -460,8 +460,7 @@ typy_get_composite (struct type *type)
 	}
       END_CATCH
 
-      if (TYPE_CODE (type) != TYPE_CODE_PTR
-	  && TYPE_CODE (type) != TYPE_CODE_REF)
+      if (TYPE_CODE (type) != TYPE_CODE_PTR && !TYPE_IS_REFERENCE (type))
 	break;
       type = TYPE_TARGET_TYPE (type);
     }
@@ -921,7 +920,7 @@ typy_template_argument (PyObject *self, PyObject *args)
   TRY
     {
       type = check_typedef (type);
-      if (TYPE_CODE (type) == TYPE_CODE_REF)
+      if (TYPE_IS_REFERENCE (type))
 	type = check_typedef (TYPE_TARGET_TYPE (type));
     }
   CATCH (except, RETURN_MASK_ALL)