@Override
				public int compare(Register r1, Register r2) {
					return r2.getBitLength() - r1.getBitLength();
				}
Sets up the change address sets, Diffs between the various program versions,
and Merges from various versions to the resulting program.
Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/ProgramContextMergeManager.java