Rename declaration-definition change category.

Rename declaration-definition change category.

This patch renames CLASS_DECL_ONLY_DEF_CHANGE_CATEGORY to
TYPE_DECL_ONLY_DEF_CHANGE_CATEGORY.

	* include/abg-comparison.h (TYPE_DECL_ONLY_DEF_CHANGE_CATEGORY):
	Rename CLASS_DECL_ONLY_DEF_CHANGE_CATEGORY into this.
	(EVERYTHING_CATEGORY): In the value of this enumerator, rename
	CLASS_DECL_ONLY_DEF_CHANGE_CATEGORY into
	TYPE_DECL_ONLY_DEF_CHANGE_CATEGORY.
	* src/abg-comp-filter.cc (categorize_harmless_diff_node):
	Likewise.
	* src/abg-comparison.cc (get_default_harmless_categories_bitmap):
	Likewise.
	(operator<<(ostream& o, diff_category c)): Likewise.
	* src/abg-default-reporter.cc (default_reporter::report): Likewise
	in the overload for class_or_union_diff.
	* src/abg-leaf-reporter.cc (leaf_reporter::report): Likewise in
	the overload for class_or_union_diff.

Signed-off-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>