Bug 18904 - Fix support for C++ rvalue references

Bug 18904 - Fix support for C++ rvalue references

	* src/abg-comparison.cc (reference_diff::has_changes): Just
	compare the references, rather than assuming that the change can
	only be on underlying types.
	(reference_diff::report): Describe lvalue/rvalue changes for
	references.
	* src/abg-ir.cc (reference_type_def::reference_type_def): Properly
	set the name for an rvalue reference.
	(equals): For references, compare lvalue-ness too.
	(reference_type_def::get_qualified_name): Properly set rvalue
	reference names.
	* tests/data/test-diff-filter/test30-pr18904-rvalueref-liba.so:
	New test input.
	* tests/data/test-diff-filter/test30-pr18904-rvalueref-libb.so:
	New test input.
	* tests/data/test-diff-filter/test30-pr18904-rvalueref-report0.txt:
	New test reference output.
	* tests/data/Makefile.am: Add the new files to source
	distribution.
	* tests/test-diff-filter.cc (in_out_specs): Run the new tests.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>