libgccjit: Allow comparing aligned int types

gcc/jit/ChangeLog:

	* jit-common.h: Add forward declaration of memento_of_get_aligned.
	* jit-recording.h (type::is_same_type_as): Compare integer
	types.
	(dyn_cast_aligned_type): New method.
	(type::is_aligned, memento_of_get_aligned::is_same_type_as,
	memento_of_get_aligned::is_aligned): new methods.

gcc/testsuite/ChangeLog:

	* jit.dg/test-types.c: Add checks comparing aligned types.