Add detach_results(), attach_result(), and append_result() methods.
Add detach_results(), attach_result(), and append_result() methods.

These low-level methods for manipulating instruction result value lists
will replace the existing secondary_result methods.

stoklund/cretonne,sunfishcode/cretonne,stoklund/cretonne,sunfishcode/cretonne,sunfishcode/cretonne,stoklund/cretonne