Fix segv when referencing a value added to history after a Guile garbage collect.

	* value.c (record_latest_value): Call release_value_or_incref
	instead of release_value.

	testsuite/
	* gdb.guile/scm-value.exp (test_value_in_inferior): Verify value added
	to history survives a gc.
Fix pr 16612.

	* guile/scm-type.c (tyscm_copy_type_recursive): Move type to its
	new eq?-hashtab.

	testsuite/
	* gdb.guile/scm-value.ep (test_value_after_death): Do a garbage
	collect after discarding symbols.