PATCH: BPs & cleanups for ARRAY_SIZE

[Jeffrey A Law]

  In message < msg0nvwoa0.fsf@mcgary.org >you write:
  > 
  >    ggc_add_rtx_root ((rtx *) const_tiny_rtx, sizeof(const_tiny_rtx)/sizeof(
  > rtx));
  > 
  > Jeff, do you prefer this new fix, or the original fix that avoids the
  > undefined (but well-trodden) behavior at miniscule expense of time &
  > space?  I haven't committed anything yet, so I can easily change it.
I slightly prefer the new solution.

jeff