private void buildRegisterRangeMap() {
		oldRegisterRangeMap = new RangeMap();
		for (Register reg : oldLanguage.getRegisters()) {
			if (reg.isBaseRegister()) {
				long min = reg.getAddress().getOffset();
				long max = min + reg.getMinimumByteSize() - 1;
				oldRegisterRangeMap.paintRange(min, max, (int) min);
			}
		}
	}
Build old register range map - assumes oldLanguage has been established
NOTE: use of RangeMap assumes max register space size of 32-bits
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/util/LanguageTranslatorAdapter.java