public void mapRegisters(RegisterMapper mapper) {
    for (SsaBasicBlock block : getBlocks()) {
      for (SsaInsn insn : block.getInsns()) {
        insn.mapRegisters(mapper);
      }
    }

    registerCount = mapper.getNewRegisterCount();
    spareRegisterBase = registerCount;
  }
Remaps unversioned registers.

@param mapper maps old registers to new.
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/SsaMethod.java