regions: optimize MAKE-BOUNDING-RECTANGLE
regions: optimize MAKE-BOUNDING-RECTANGLE

* Call COORDINATE instead of (coerce … 'coordinate)

* Compare once for each dimension instead of calling MIN and MAX for
  each dimension

Benchmark:

  (time (loop :repeat 10000000 :do (clim:make-bounding-rectangle 1 2 3 4)))

  ;;; Before
  Evaluation took:
    10.969 seconds of real time
    10.750764 seconds of total run time (10.664711 user, 0.086053 system)
    [ Run times consist of 0.143 seconds GC time, and 10.608 seconds non-GC time. ]
    98.01% CPU
    32,829,342,777 processor cycles
    3,360,000,320 bytes consed

  ;;; After
  Evaluation took:
    6.338 seconds of real time
    6.338051 seconds of total run time (6.333973 user, 0.004078 system)
    [ Run times consist of 0.143 seconds GC time, and 6.196 seconds non-GC time. ]
    100.00% CPU
    18,969,053,397 processor cycles
    3,359,998,944 bytes consed

slyrus/mcclim,slyrus/mcclim