dwarves: Initial support for rvalue_reference_type

Need to read more on http://www.artima.com/cppsource/rvalue.html, but
handling it mostly like DW_TAG_typedef so that at least references to it
are resolved, we can get its byte size, etc.

FIXME: look at the vtable parameters, some are resolving to "(null)".

Reported-by: Benjamin Kosnik <bkoz@redhat.com>
Reported-by: Mark Wieelard <mjw@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=962571
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

dwarf_loader.c

@@ -1583,6 +1583,7 @@ static struct tag *__die__process_tag(Dwarf_Die *die, struct cu *cu,
 		tag = die__create_new_function(die, cu);	break;
 	case DW_TAG_subroutine_type:
 		tag = die__create_new_subroutine_type(die, cu);	break;
+	case DW_TAG_rvalue_reference_type:
 	case DW_TAG_typedef:
 		tag = die__create_new_typedef(die, cu);		break;
 	case DW_TAG_union_type:

dwarves.c

@@ -302,6 +302,7 @@ reevaluate:
 		case DW_TAG_array_type:
 		case DW_TAG_const_type:
 		case DW_TAG_typedef:
+		case DW_TAG_rvalue_reference_type:
 		case DW_TAG_volatile_type: {
 			struct tag *tag = cu__type(cu, type->type);
 			if (type == NULL) {

dwarves.h

@@ -359,6 +359,11 @@ static inline int tag__is_typedef(const struct tag *tag)
 	return tag->tag == DW_TAG_typedef;
 }
 
+static inline int tag__is_rvalue_reference_type(const struct tag *tag)
+{
+	return tag->tag == DW_TAG_rvalue_reference_type;
+}
+
 static inline int tag__is_union(const struct tag *tag)
 {
 	return tag->tag == DW_TAG_union_type;
@@ -396,6 +401,7 @@ static inline int tag__is_type(const struct tag *tag)
 	return tag__is_union(tag)   ||
 	       tag__is_struct(tag)  ||
 	       tag__is_typedef(tag) ||
+	       tag__is_rvalue_reference_type(tag) ||
 	       tag__is_enumeration(tag);
 }
 
@@ -410,6 +416,7 @@ static inline int tag__is_tag_type(const struct tag *tag)
 	       tag->tag == DW_TAG_base_type ||
 	       tag->tag == DW_TAG_const_type ||
 	       tag->tag == DW_TAG_pointer_type ||
+	       tag->tag == DW_TAG_rvalue_reference_type ||
 	       tag->tag == DW_TAG_ptr_to_member_type ||
 	       tag->tag == DW_TAG_reference_type ||
 	       tag->tag == DW_TAG_subroutine_type ||