public boolean equalsUsingSimpleType(RegisterSpec other) {
    if (!matchesVariable(other)) {
      return false;
    }

    return (reg == other.reg);
  }
Like {@code equals}, but only consider the simple types of the registers. That is, this
compares {@code getType()} on the types to ignore whatever arbitrary extra stuff might be
carried around by an outer {@link TypeBearer}.

@param other {@code null-ok;} spec to compare to
@return {@code true} iff {@code this} and {@code other} are equal in the stated way
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/code/RegisterSpec.java