Refactor the use of ``$(DESTDIR)$(PREFIX)`` in ``MakeRuleCmd`` class so that it is exposed via a public method (``install_root()``) so that is can be used externally. Also refactor the existing methods to use it.
Refactor the use of ``$(DESTDIR)$(PREFIX)`` in ``MakeRuleCmd``
class so that it is exposed via a public method (``install_root()``)
so that is can be used externally. Also refactor the existing methods
to use it.

seahorn/z3,kyledewey/z3,seahorn/z3,mschlaipfer/z3,kyledewey/z3,kyledewey/z3,mschlaipfer/z3,kyledewey/z3,seahorn/z3,seahorn/z3,seahorn/z3,mschlaipfer/z3,mschlaipfer/z3,kyledewey/z3,seahorn/z3,mschlaipfer/z3,kyledewey/z3,mschlaipfer/z3