* Use 9 digits instead of 11 digits in efx and efx8.

* Update the domain and range of comments for the polynomial
  approximations, including using the the correct variable names
  (e.g., pp(x) instead of p(x)).

* Use hex values of the form 0x3e0375d4 instead of 0x1.06eba8p-3,
  which was obtained from printf("%.6a").

* In the domain [0.84375, 1.25], qa(x) can be reduced from a 4th
  order polynomial to 3rd order.

* In the domain [1.25,1/0.35], sa(x) can be reduced from a 4th
  order polynomial to 3rd order.

* In the domain [1/0.35, 11], the 4th order polynomials rb(x) and
  sb(x) can be reduced to 2nd and 3rd order, respectively.
Implement pmap_unwire().  See r268327 for the motivation behind this change.